God forgives all of our sin, regardless of how “big” or “small” that sin may be . . . because of his great and enduring love.
What that means, from God’s perspective, is that he has forgotten our sins and is not holding us accountable for them. They have already been paid for. God has already forgiven our sin—past, present and future—in the shedding of blood and sacrifice of his Son, Jesus Christ.
When we ask for forgiveness it is for our benefit. In other words, asking for forgiveness acknowledges our sin and rebellion against God and allows us to turn towards him in an attitude of repentance. It is an act of love.
It is important to remember that Christians aren’t perfect, only forgiven. There are two kinds of people in the world, not the good and the bad; but, rather, the bad who know it and the bad who don’t.