Some people think that the way to be saved is by doing penance. They think that if they feel sorry about their wrongs, God will forgive their sins. Many religions practice asceticism and mortification, thinking that the more they make their bodies suffer, the more they will obtain favor from God. They think that God is a God who enjoys seeing man suffer. This also is an absurd thought. In reality, doing penance is simply a way of bribing the conscience. When a man sins, his conscience condemns him, and he thinks that by hurting himself he will appease his conscience by telling himself that he has suffered recompense for his wrongs.
The third way that man tries to absolve himself from guilt is by trying to forget about his sins. He thinks that, given enough time, he will not remember his sins anymore, and that as long as he himself does not remember them, God will not remember them either. Such people are like the ostrich which tries to hide in the sand, thinking that by not seeing his danger, his danger will leave him. However, the fact that sin is removed from our memory does not mean that it is removed from God's record. To try to absolve one's sin by forgetting about it is also a foolish thing to do.
According to the Bible, God's righteousness requires that all sins be judged. The only way that sin can be judged righteously is by the way of death. Hebrews 9:22 says that "without shedding of blood there is no forgiveness." In order for God to judge and then to forgive our sins, there must be the shedding of blood; that is, there is the need of death. Any way of redemption that does not involve death cannot meet the righteous requirement of God, but comes short of God's standard.
In the Old Testament God required the death of animals as sacrifices. When a man sinned, he had to offer a lamb or a bull and had to kill the sacrifice before God's righteous demand could be appeased. Although this way allowed God to pass over the man's sins, it was not meant to be the final solution to the problem of sin. In the New Testament God's solution to the problem of sin is to send His only begotten Son, Jesus Christ, as the unique sacrifice, to replace all the Old Testament animal sacrifices (Heb. 10:1-18). He caused Jesus to die on behalf of all mankind (1 Pet. 3:18). By executing His judgment on Jesus Christ, God's only begotten Son, man's sin is judged, and the problem of sin is finally and eternally solved (Rom. 8:3; Heb. 9:26). In the Old Testament man had to do something to take care of his sins; he had to offer up animals as sacrifices. But in the New Testament everything that needs to be done has been done already by God in Jesus Christ. Christ is the perfect sacrifice and the eternal sacrifice. There is nothing more that man can add to this sacrifice to improve what God has done. This is why in the New Testament man does not need to do any good works to save himself; God has done everything for man already.