No one, as long as he is clothed with this body of flesh, will be immune to fleshly desires. Even Jesus was tempted (Matthew 4:1ff; Hebrews 2:18), but like Him the Christian can be so committed to God that he will be adamantly determined not to give in to such desires. Indeed, this is what Christ expects him to do (Matthew 16:24). He may sin in a moment of weakness, but sin will not be the rule of his life (cf. Romans 7:21ff). On the contrary, the rule is that he does not sin; the exception to the rule is that occasionally he does, but his determination to walk with God will cause him to quickly repent of his weakness and sin and ask for forgiveness. It is because he has such an attitude of submission, and such a determined commitment, that Jesus’ blood is said to continually cleanse him of his sins (I John 1:7-10).
No one should assume, however, that such cleansing will automatically continue if he refuses to repent, no matter how trivial and insignificant the sin may seem to be. The commission of even one sin, for which one will not or does not repent, will result in his alienation from God (James 2:10).
Simon is an inspired example of this (Acts 8:9-24). Although some claim he was never a believer, Luke clearly says that he was (Acts 8:13) and that he was baptized just as the other Samaritans were. Simon sinned by lusting for, and trying to purchase, the power of imparting miraculous gifts of the Holy Spirit through the laying on of hands (Acts 8:18-19). Peter, in rebuking him, named the sin he had committed: “Thou hast thought to obtain the gift of God with money” (Acts 8:20).
He charged that Simon’s heart was “not right before God” (Acts 8:21) and that he was “in the gall of bitterness and in the bond of iniquity” (Acts 8:23). Although Simon was a Christian, who can doubt that he was cut off from God’s favor at that moment and fallen from grace? Yet, Peter told him to repent of his wickedness and pray to the Lord “if perhaps the thought of thy heart shall be forgiven thee” (Acts 8:22). It would appear that Simon believed what Peter told him, for he asked the apostle to pray for him (Acts 8:24).
Since Peter told Simon that he would “perish” in his present condition (Acts 8:20), it is ludicrous to think that Jesus’ blood was cleansing him of his sin before he repented. On the other hand, if he obeyed Peter’s command, there is every reason to believe that Jesus’ blood did continue to cleanse him after his repentance and prayer. Since God is no respecter of persons (Romans 2:11), He likewise expects repentance and prayer from Christians today whenever awareness of sin takes place—if they expect the blood of Christ to continue cleansing them.