As a Baptist, I believe that the only proper subjects of baptism are professing believers in Jesus Christ. And the purpose of baptism is not to bring about regeneration, but to express one’s faith in Christ through a visible act of repentance. And the only proper mode of baptism is immersion in water.
I admit that these three beliefs together are a minority position in the life of the church, but all three of these beliefs can be found in the writings of the early and medieval church:
Subjects
“But before the baptism let the baptizer fast, and the baptized, and whatever others can; but you shall order the baptized to fast one or two days before” (Didache, Chapter 7).
“As many as are persuaded and believe that what we teach and say is true, and undertake to be able to live accordingly, are instructed to pray and to entreat God with fasting, for the remission of their sins that are past, we praying and fasting with them” (Justin Martyr, First Apology, Chapter 61 on Christian Baptism).
“That baptismal washing is a sealing of faith, which faith is begun and is commended by the faith of repentance. We are not washed in order that we may cease sinning, but because we have ceased, since in heart we have been bathed already” (Tertullian, On Repentance, Chapter 6).
“And so, according to the circumstances and disposition, and even age, of each individual, the delay of baptism is preferable; principally, however, in the case of little children. . . . The Lord does indeed say, ‘Forbid them not to come unto me.’ Let them ‘come,’ then, while they are growing up; let them ‘come’ while they are learning, while they are learning whither to come; let them become Christians when they have become able to know Christ” (Tertullian, On Baptism, Chapter 18).
“They who are about to enter baptism ought to pray with repeated prayers, fasts, and bendings of the knee, and vigils all the night through, and with the confession of all bygone sins” (Tertullian, On Baptism, Chapter 20).
“Those who are to receive baptism shall fast on the Preparation of the Sabbath. On the Sabbath, those who are to receive baptism shall all gather together in one place chosen according to the will of the bishop. They shall be commanded to pray and kneel. Then, laying his hand on them, he will exorcise every foreign spirit, so that they flee from them and never return to them” (Hippolytus, Apostolic Tradition, Chapter 20, Sections 7-8).
“Be it so, some will say, in the case of those who ask for Baptism; what have you to say about those who are still children, and conscious neither of the loss nor of the grace? Are we to baptize them too? Certainly, if any danger presses. For it is better that they should be unconsciously sanctified than that they should depart unsealed and uninitiated. . . . But in respect of others I give my advice to wait till the end of the third year, or a little more or less, when they may be able to listen and to answer something about the Sacrament; that, even though they do not perfectly understand it, yet at any rate they may know the outlines; and then to sanctify them in soul and body with the great sacrament of our consecration. For this is how the matter stands; at that time they begin to be responsible for their lives, when reason is matured, and they learn the mystery of life (for of sins of ignorance owing to their tender years they have no account to give), and it is far more profitable on all accounts to be fortified by the Font, because of the sudden assaults of danger that befall us, stronger than our helpers” (Gregory of Nazianzus, Orations, Oration 40, Section 28).
“Gregory [of Nazianzus] is one of the so-called Cappodocian Fathers, along with Gregory of Nyssa and his brother Basil the Great. Interestingly, none of the three, despite being the children of Christian parents, was baptized while an infant. Gregory of Nazianzus, whose father was a bishop, was not baptized until he was about 30 years old” (Steven A. McKinion, “Baptism in the Patristic Writings,” in Believer’s Baptism, p. 182)
“Indeed, what we know of the ages at which those from strong Christian families who became leaders in the church in the fourth century were baptized offers no certain examples of baptism in childhood. The list includes Ephraem the Syrian, Basil of Caesarea, Gregory of Nyssa, Gregory of Nazianzus, John Chrysostom, Ambrose, Jerome, Rufinus, Paulinus of Nola, and Nazianzus’s father Gregory, sister Gorgonia, and brother Caesarius” (Everett Ferguson, Baptism in the Early Church, p. 626-627. See also Palladius, Dialogue on the Life of St. John Chrysostom, Chapter 5).
“Severus earnestly desired to receive baptism there and also to become, he, too, a signed one among the lambs of the house of God. For this Mother [faith] had still not been acquired by him, because in the country of his people, they used to baptize none except [grown] men” (Robert Bishop, Life of Severus of Antioch. As cited by Kathleen McVey, “The Life of Severus of Antioch by Robert Bishop of the Arabians” [Ph.D. dissertation, Harvard University, 1997], p. 95. Severus lived from 465-538. As cited by Everett Ferguson, Baptism in the Early Church, p. 632).
“Next it must be noted that at first the traditional grace of baptism was given only to those who had already matured in both body and mind, they would be able to know and understand what effort must follow after baptism, what must be confessed and believed; in short, what must be observed by those reborn in Christ” (Walahfrid Strabo in the ninth century, De exordiis et incrementis quarundam in observationibus ecclesiasticus rerum, Chapter 27. As cited by Everett Ferguson, Baptism in the Early Church, p. 633).
“In the first generation one did not baptize infants, but those who attained a proper age were called catechumens. It is to these that one preached baptism and taught the Christian religion for three years, and they were baptized” (Macarius, Bishop of Memphis in Egypt in the tenth century. As cited by Everett Ferguson, Baptism in the Early Church, p. 632).
“There is general agreement that there is no firm evidence for infant baptism before the latter part of the second century. . . . Arguments against the originality of baby baptism, in addition to its lack of early attestation, include: the essential nature ascribed to verbal confession and repentance; the liturgy designed for persons of responsible age; size of baptisteries; and the lack of an agreed theology to support it. . . . The most plausible explanation for the origin of infant baptism is found in the emergency baptism of sick children expected to die soon so that they would be assured of entrance into the kingdom of heaven. There was a slow extension of the practice of baptizing babies as a precautionary measure. It was generally accepted, but questions continued to be raised about its propriety into the fifth century. It became the usual practice in the fifth and sixth centuries” (Everett Ferguson, Baptism in the Early Church, p. 856-857).
“[Baptism cannot] be of any advantage to a little child, who neither wills nor runs, who knows nothing of faith, and is altogether ignorant of his own good and salvation in whom there can be no desire of regeneration, and from whom no confession of faith can be expected” (Confession of faith of the followers of Gundolfo of Italy in 1025 at the Synod of Arras. As cited by Pierre Allix, Some Remarks Upon the Ecclesiastical History of the Ancient Churches of Piedmont, p. 104).
“From these words of the Lord (they say) it is evident that no one can be saved unless he believes and is baptized, that is, unless he have the Christian faith, for neither one of these without the other will save him. Hence infants, although they are baptized by you, nevertheless, because they cannot believe, since they are as yet too young, are not at all saved. It is useless, therefore, and vain when you baptize one with water, which indeed cleanses the body from filth, as one usually takes a bath, but does not at all cleanse the soul from sin. But we wait for the time when a person, after he has known God, is ready to believe on Him, and so baptize him – not rebaptize him, as you accuse us – but baptize him, since he had not before been baptized with baptism which cleanses from sin. . . . But I know why you thus deride (infant baptism) and declare that one cannot be saved by the faith of another, because you deny many things in your boasting among the ignorant and unlearned” (Peter the Venerable in his treatise against Peter of Bruys and the Petrobrusians. As cited by Joseph Cowley Reagan, “Did the Petrobrusians Teach Salvation by Faith Alone?” in The Journal of Religion, VII (1927), p. 89).
“Thus they render void the priesthood of the Church and condemn its sacraments, save baptism alone, and this [they approve] only for adults, who, they say, are baptized by Christ, no matter who may actually administer the sacrament. They do not believe in infant baptism because of the text of the Gospel, ‘He that believeth and is baptized shall be saved’” (Eberwin of Steinfeld to Bernard of Clairvaux about the beliefs of Henry of Lausanne and the Henricians. As cited by Walter L. Wakefield and Austin P. Evans, Heresies of the High Middle Ages, p. 131).
“On the baptism of children: You put together a captious and slanderous attack upon infant baptism by following, without much insight, the verbal formulas and noting in them a defect of misrepresentation where none exists. . . . This you do because you ignore original sin, washed away by baptism. . . . Therefore, just as carnal circumcision was once performed out of necessity, so now is the ablution of water, lest the soul of the child be taken away from his people” (The Letter of Master Vacarius against the Errors of Hugo Speroni. As cited by Walter L. Wakefield and Austin P. Evans, Heresies of the High Middle Ages, p. 154-155).
“Secondly, they condemn all the Sacraments of the Church; in the first place, as to baptism, they say that the Catechism is nothing—also, that the ablution which is given to infants profits nothing” [Quod ablutlo quae datur infantibus nihil prosit] (The Dominican inquisitor Reinerius Saccho on “the sect of Poor Men of Lyons” or Waldensians. As cited by S. R. Maitland, Facts and Documents Illustrative of the History, Doctrine, and Rites of the Ancient Albigenses and Waldenses, p. 410).
“We come now to the Rebaptizers, whose particular error is to baptize a second time. Their heresy arose at the same time as that of the Leonists [Waldensians]” (Summa contra hereticos by Peter of Verona written between 1235-1238. As cited by Walter L. Wakefield and Austin P. Evans, Heresies of the High Middle Ages, p. 277).
Purpose
“And further, as you are not ignorant, the Holy Spirit is found to have been given to men who believe, by the Lord without baptism of water, as is contained in the Acts of the Apostles after this manner: ‘While Peter was still speaking these words, the Holy Ghost fell upon all them who heard the word. And they who were of the circumcision which believed were astonished, as many as came with Peter, because that on the Gentiles also was poured out the gift of the Holy Spirit. For they heard them speak with their tongues, and they magnified God. Then answered Peter, Can any man forbid water, that these should not be baptized, who have received the Holy Ghost as well as we? And he commanded them to be baptized in the name of Jesus Christ.’ Even as Peter also subsequently most abundantly taught us about the same Gentiles, saying: ‘And He put no difference between us and them, their hearts being purified by faith.’ And there will be no doubt that men may be baptized with the Holy Ghost without water,—as thou observest that these were baptized before they were baptized with water; that the announcements of both John and of our Lord Himself were satisfied,—forasmuch as they received the grace of the promise both without the imposition of the apostle’s hands and without the laver, which they attained afterwards. And their hearts being purified, God bestowed upon them at the same time, in virtue of their faith, remission of sins; so that the subsequent baptism conferred upon them this benefit alone, that they received also the invocation of the name of Jesus Christ, that nothing might appear to be wanting to the integrity of their service and faith” (An Anonymous Treatise on Rebaptism, Chapter 5).
“And what wilt thou determine against the person of him who hears the word, and haply taken up in the name of Christ, has at once confessed, and has been punished before it has been granted him to be baptized with water? Wilt thou declare him to have perished because he has not been baptized with water? Or, indeed, wilt thou think that there may be something from without that helps him to salvation, although he is not baptized with water? Thy thinking him to have perished will be opposed by the sentence of the Lord, who says, ‘Whosoever shall confess me before men, him will I also confess before my Father which is in heaven;’ because it is no matter whether he who confesses for the Lord is a hearer of the word or a believer, so long as he confesses that same Christ whom he ought to confess; because the Lord, by confessing him, in turn Himself graces His confessor before his Father with the glory of his martyrdom” (An Anonymous Treatise on Rebaptism, Chapter 11).
“Which Spirit also filled John the Baptist even from his mother’s womb; and it fell upon those who were with Cornelius the centurion before they were baptized with water. Thus, cleaving to the baptism of men, the Holy Spirit either goes before or follows it; or failing the baptism of water, it falls upon those who believe” (An Anonymous Treatise on Rebaptism, Chapter 15).
“Now if this righteousness be observed, there will be no need of Baptism; and if broken, Baptism cannot avail to salvation. This is the sum of our justification, to which the use of Baptism can superadd nothing, since this is the end of all apostolical and evangelical institutions” (Confession of faith of the followers of Gundolfo of Italy in 1025 at the Synod of Arras. As cited by Pierre Allix, Some Remarks Upon the Ecclesiastical History of the Ancient Churches of Piedmont, p. 104).
“This heresy and all who profess it, which today has been found to have conspired against the true and catholic Church – to wit, which holds that baptism will not avail toward washing away the stain of original sin, or of sins actually committed” (Condemnation of the Beliefs of Gundolfo of Italy in 1025 at the Synod of Arras. As cited by Walter L. Wakefield and Austin P. Evans, Heresies of the High Middle Ages, p. 85).
“There were heretics who denied that the substance of the bread and wine which priests bless on the altar is really changed into the body and blood of Christ. They also said that the sacrament of baptism of infants has no efficacy for salvation” (Description of a heresy in Ivoy, France in 1122 of those who have been called followers of Berengar of Tours. As cited by Walter L. Wakefield and Austin P. Evans, Heresies of the High Middle Ages, p. 105).
“You must either say that we [Catholics] are heathen, or if you avoid that, you must admit that we have faith in Christ and the Gospel, and the Martyrs were saved by faith alone and martyrdom, without baptism. . . . . Now if you admit this, that you say some can be saved by their faith alone without baptism, why do you not believe that some can be saved by baptism alone without faith of their own? If the Martyrs are saved by their faith alone without baptism, why cannot children be saved by baptism alone without faith” (Peter the Venerable in his treatise against the Petrobrusians. As cited by Joseph Cowley Reagan, “Did the Petrobrusians Teach Salvation by Faith Alone?” in The Journal of Religion, VII (1927), p. 89).
“‘Do you believe that water could work your salvation.’ He answers, ‘I do not believe it.’ — ‘You must renounce that veil which the priest placed on your head when you were baptized.’ He must answer, ‘I renounce it'” (Raynaldus on the initiation ceremony of a group of Waldensians. As cited by S. R. Maitland, Facts and Documents Illustrative of the History, Doctrine, and Rites of the Ancient Albigenses and Waldenses, p. 394).
“We consider the Sacraments as signs of holy things, or as the visible emblems of invisible blessings. We regard it as proper and even necessary that believers use these symbols or visible forms when it can be done. Notwithstanding which, we maintain that believers may be saved without these signs, when they have neither place nor opportunity of observing them” (Article 12 of The Waldensian Confession of 1120 [almost certainly written long after 1120 as this was before the time of the Waldensians]. As cited by Samuel Morland, The History of the Evangelical Churches of the Valleys of Piemont, p. 34).
Mode
“This meaneth, that we indeed descend into the water full of sins and defilement, but come up, bearing fruit in our heart, having the fear of God and trust in Jesus in our spirit” (Epistle of Barnabas 11:10).
“Those whom the water of baptism has submerged” (Tertullian, On the Resurrection, Chapter 52).
“With so great simplicity, without pomp, without any considerable novelty of preparation, finally, without expense, a man is dipped in water” (Tertullian, On Baptism, Chapter 2).
“In the same way as the act of baptism itself too is carnal, in that we are plunged in water” (Tertullian, On Baptism, Chapter 7).
“He commands them to baptize into the Father and the Son and the Holy Ghost, not into a unipersonal God. And indeed it is not once only, but three times, that we are immersed into the Three Persons, at each several mention of Their names” (Tertullian, Against Praxeas, Chapter 26).
“Then, after these things, the bishop passes each of them on nude to the elder who stands at the water. They shall stand in the water naked. A deacon, likewise, will go down with them into the water. When each of them to be baptized has gone down into the water, the one baptizing shall lay hands on each of them” (Hippolytus, Apostolic Tradition, Chapter 21, Sections 11-12).
“And some of them try to argue that they only administer a sound and perfect, not as we, a mutilated and curtailed baptism, which they are in such wise said to designate, that immediately they have descended into the water” (An Anonymous Treatise on Rebaptism, Chapter 16).
“If any bishop or presbyter does not perform the three immersions of the one admission, but one immersion, which is given into the death of Christ, let him be deprived; for the Lord did not say, Baptize into my death, but, Go and make disciples of all nations, baptizing them into the name of the Father, and of the Son, and of the Holy Ghost. Therefore, O bishops, baptize thrice into one Father, and Son, and Holy Ghost, according to the will of Christ, and our constitution by the Spirit” (Apostolic Constitutions, Book 8, Section 47, Canon 50).
“Thou hast the baptism as a surety of the abode of heaven. Thou didst imitate, in the sinking down, the burial of the Master; but thou didst rise again from thence, before works witnessing the works of the resurrection” (Athanasius, Discourse on Holy Passover, Chapter 5).
“By imitating, through baptism, the burial of Christ. For the bodies of the baptized are, as it were, buried in the water” (Basil the Great, On the Spirit, Chapter 35).
“By going down into the water, and being in a manner buried in the waters, as He was in the rock, art raised again walking in newness of life” (Cyril of Jerusalem, Catechetical Lectures, Lecture 3, Section 12).
“Let us, therefore, be buried with Christ by the baptism, that we may also rise with him; let us go down with him, that we may also be exalted with him; let us come up with him, that we may also be glorified with him” (Gregory of Nazianzus, On Holy Baptism, Discourse 40).
“And we in receiving Baptism, in imitation of our Lord and Teacher and Guide, are not indeed buried in the earth, but coming to the element akin to earth, to water, we conceal ourselves in that as the Saviour did in the earth” (Gregory of Nyssa, On the Baptism of Christ).
“Baptism is a likeness of death when you go down into the water, and when you rise again it becomes a likeness of resurrection” (Ambrose, The Sacraments, 2.7.20).
“For when we immerse our heads in the water, the old man is buried as in a tomb below, and wholly sunk forever; then as we raise them again, the new man rises in its stead” (John Chrysostom, Homily 25 on the Gospel of John).
“The Saviour Himself does not preach the kingdom of heaven until by His baptismal immersion” (Jerome, Letter to Oceanus).
“Therefore, baptism is signified by the sign of Christ, that is, by the water in which you are immersed and through which you pass” (Augustine, Sermons on the Liturgical Seasons, Sermon 213, Section 8).
“For in the baptismal office death ensues through the slaying of sin, and threefold immersion imitates the lying in the tomb three days, and the raising out of the water is like Him that rose again from the tomb” (Pope Leo the Great, Letter 16).
“But with respect to trine immersion in baptism, no truer answer can be given than what you have yourself felt to be right; namely that, where there is one faith, a diversity of usage does no harm to holy Church. Now we, in immersing thrice, signify the sacraments of the three days’ sepulture” (Pope Gregory the Great, Letter to Leander, Book 1, Letter 43).
“Baptism is an image of the death of Christ. For by the three immersions, baptism signifies the three days of our Lord’s entombment” (John of Damascus, An Exposition of the Orthodox Faith, Book 4, Chapter 9).
“For one baptism is spoken of, as also one faith, because of the doctrine respecting the initiation, being one in all the Church, which has been taught to baptize with invocation of the Trinity, and to symbolize the Lord’s death and resurrection by the threefold sinking down and coming up” (Theophylact of Ohrid, Commentary on Nahum, Chapter 1).
“The Christian literary sources, backed by secular word usage and Jewish religious immersions, give an overwhelming support for full immersion as the normal action. Exceptions in cases of a lack of water and especially of sickbed baptism were made. Submersion was undoubtedly the case for the fourth and fifth centuries in the Greek East and only slightly less certain for the Latin West” (Everett Ferguson, Baptism in the Early Church, p. 857).
See this article for quotations from paedobaptist scholars who argue that immersion was the mode of baptism practiced by the first-century church.