Evangelicals quite rightly criticize the Roman Catholic Church for its insistence that it is possible for Christians to lose their state of grace through mortal sin, and that the only way to restore such a person is through the sacrament of penance. In our formal theology we insist that there is no need for penance to deal with sins after baptism.
The trouble is, our formal theology is often rather different from our day-to-day informal theology. And this informal theology often assumes that our sins change God's view of us, and in order to be restored to God's favour, we need to do something, or, worse, to feel something. In other words, many Evangelicals are practical Romanists, we feel we need some sort of penance for our sins. Of course, I am not referring to people who make a profession of faith, but have no qualms at all about sinning with a high hand, but to Christians who fall into sin and then feel that God is angry with them because of that sin.
Here is the good news. We have a representative High Priest in heaven for us, Jesus Christ the Righteous, who always appears in the presence of God the Father to make intercession for us. And the fact that He is there means this: God is on our side whether we are victorious or defeated, when we are able to resist temptation and when we yield to it. "If we confess our sins [God] is faithful and just to forgive us our sins." Now, we would expect that text to read, 'He is merciful and gracious to forgive us our sins,' but it does not. Why is this? It is because Jesus died for our sins on the cross, it is because the forgiveness of sins was purchased for us there, and thus if God does not forgive the sins of His people He would be unfaithful to His promise of the forgiveness of sins, and unjust in not pardoning the sins Jesus died for.
Christian, you do not need a penance. The price of sin has been fully paid. You do need a confessional, and you have that in Jesus, the sympathising High Priest who bids you to come unto Him and confess your sins in prayer. And having confessed that you are a sinner, Jesus speaks those wonderful words, "Your sins are forgiven you."