No one who asks God for forgiveness can be confident that they won’t commit the same sin again. In fact, our natures are so contaminated by sin that we often do. When Peter asked Jesus whether we are obligated to forgive a person who sins against us seven times (Peter’s “seven times” more than doubled the rabbinic prescription), Jesus said: “I do not say to you, up to seven times, but up to seventy times seven” (Matthew 18:22 NKJV).
Jesus made it clear that God’s primary concern is not mere outward behavior, but the condition of the heart Matthew 23:25-26; Mark 7:5-9; Luke 11:42-44; Luke 11:42-44. Therefore the sincerity of the confession is what counts.
Unfortunately, we can be sincere in our repentance and confession and still fall into sin again. Because believers continue to be influenced by the “flesh”—the fallen aspect of their personalities—in this world they are incapable of perfect sincerity. At times they are more vulnerable to temptation than at other times. With the passage of time, the strong awareness of evil and the ugliness of sin that brought us to repentence often fades.
Sincere confession of sin is a heartfelt acknowledgment that our sin is wrong, that we don’t want to continue in it, and that we are ready to exert ourselves—under the guidance of the Holy Spirit—to resist it. God doesn’t expect perfection, because none of us are capable of achieving it, but He does expect sincerity.
Sin is highly addictive, and when we’re not on our guard we can easily succumb to the false sense of relief we experience when we surrender to our compulsions. We need to be aware of sin’s addictive nature. Like someone who is attempting to quit smoking or drinking, the worst thing we can do is to give up on our desire to change or believe we can never change, even though we relapse in moments of weakness.
As we experience increasing freedom from sin, we will experience an increasing awareness of evil and understand more deeply how sin carries its own penalty. Each time genuine believers relapse into sin, they will experience more conviction and a more painful awareness of sin’s destructiveness. Each time they repent and confess their sins, they will be purer, stronger, and less likely to relapse.
Of course, some sins are so serious that even sincere repentance can’t erase their earthly consequences. Sins like murder and adultery can be forgiven by God in the ultimate sense and by fellow Christians in the sense of hoping for a sinner’s restoration, but the damage such sins inflict usually cannot be undone in this life, and consequences such as imprisonment or divorce may be unavoidable.