The Bible paints a grim picture of fallen man. Before and after the flood it is says that, “Every intention of the thoughts of his heart was only evil continually” (Gen 6:5; 8:21). Even after salvation we still continue to sin (1 John 1:8-10). Proverbs 20:9 says, “Who can say, ‘I have made my heart pure; I am clean from my sin'”? Ecclesiastes 7:20 echoes the same thought: “Surely there is not a righteous man on earth who does good and never sins.” Other verses that refute the silly idea of sinless perfection include 1 Kings 8:46; Psalm 19:12; 143:2; Philippians 3:12; and James 3:2.
Even the good works of the wicked are not good in God’s eyes because they are not done for his glory (1 Cor 10:31). Romans 14:23 says “whatever does not proceed from faith is sin.” This is why the righteous deeds of the wicked are as filthy rags in the sight of God which merit nothing (Isa 64:6). This is in contrast to the good deeds of believers which do please God because they are done in faith and for his glory (Eph 2:10). The life of unregenerate man is one of willing enslavement to sin (John 8:34; Tit 3:3). They do not seek after God (Rom 3:11). They are slaves of Satan (Acts 26:18; 2 Cor 4:4; Eph 2:2) and are by nature children of wrath (Eph 2:3). The phrase “by nature” is important because it contradicts the Pelagian idea that we are born into the world guiltless. We are naturally under the sentence of God’s wrath because of the sin of Adam rather than being under the sentence of God’s wrath later on because of the popular concept of an “age of accountability” (Rom 5:12-19; 1 Cor 15:22). From conception we are in sin (Psa 51:5). Infants die because they are fallen in Adam even though they have not sinned personally. We are all condemned in Adam the same way Christians are declared righteous in Christ – imputation (Rom 5:19; 2 Cor 5:21). Loraine Boettner has a good summary of infant salvation in the Reformed tradition which explains how original sin and infant salvation can be reconciled.
Romans 8:7-8 says, “For the mind that is set on the flesh is hostile to God, for it does not submit to God’s law; indeed, it cannot. Those who are in the flesh cannot please God.” Those who are not Christians cannot do anything that pleases God because of their bondage to sin and hostility to God. The problem is not simply that they are sinners, but that they are rebels (Matt 21:38-40). They are hostile to God. They hate God and would murder him if given the chance. That is exactly what they did to Jesus on the cross. This is why regeneration is essential before anyone can believe the gospel. Saving faith and repentance are pleasing to God and only those in the Spirit can do such a thing (Rom 8:8-9; 1 John 5:1). God must change their affections and desires to love Christ and give them his Spirit (Eze 36:26-27; John 3:3-5). Only those who are already in the Spirit can say that Jesus is Lord (1 Cor 12:3; Rom 10:9). Fallen man is morally unable to believe in Christ because he is his enemy (John 6:44; Rom 5:10; 2 Tim 2:25-26).
An analogy that is helpful is Genesis 37:4 about Joseph’s brothers: “But when his brothers saw that their father loved him more than all his brothers, they hated him and could not speak peacefully to him.” They could not speak to him because they hated him. They could not because they would not and they would not because of the hatred that was in their heart. God had to change the hearts of Joseph’s brothers before they would love him (Gen 50:18-20). So also, God must change our hearts before we have the moral ability and desire to love Christ for who he is. That is why anyone who is in Christ is a new creation and the old ways of life have passed away (2 Cor 5:17). As Charles Spurgeon has said, while we may continue to sin until glorification, our sin is a dying and condemned thing.
One of the implications of the doctrine of man’s radical depravity is that we cannot expect non-Christians to come to us. They are living in active rebellion against God and therefore we have to go to them. They must be confronted with the gospel through active evangelism and outreach. We cannot expect those who hate God to willingly come hear a message that they do not want to believe in. Changing the gospel to accommodate their hatred of the one true God will simply fill the membership of the church with unregenerate hypocrites and create numerous church discipline problems. It is only through the preaching of the true gospel that God changes people to love what they formerly hated and hate what they formerly loved. When we are ashamed of the radical demands of the gospel and preach an entertaining message to draw a crowd, we preach a different gospel and have ceased to be ambassadors for Christ.