Sometimes we've done things that seem so wrong that we feel God can't forgive us. While those things may indeed be very wrong, an amazing thing about God is that He knows we are sinners and He is always willing to forgive us.
Remember what Jesus said to the adulterer:
"Neither do I condemn you; go and sin no more." (John 8:11)
Forgiveness doesn't mean saying the offense was OK, or didn't matter. Forgiveness is about "letting go", putting it in the past and moving on. Not holding it against the offender. And so it is with God's forgiveness. It doesn't take away the offense, or mean it doesn't matter.
The Lord offers forgiveness to everyone, whatever the offense. But that forgiveness only takes effect and is useful if we accept the forgiveness. How do we do that?
A key part of forgiveness of our sins is taking action - the second point in the John 8 passage above. We are called to repent of our sins, and go forward to work on our spiritual growth, trying to do better; trying to do what God wants.
The Bible tells us that repentance is required for the forgiveness of sins (Mark 1:4; Luke 3:3). And repentance is more than just feeling sorry. When we truly repent, we want to stop doing the sin; we work at resisting that temptation. That's really what salvation is all about: the Lord can change our hearts when we acknowledge specific sins and work to avoid it going forward. Each time we resist, it gets easier to resist next time. When we do that, over time the Lord can change us and help us more away from that evil. Slowly we can accept forgiveness for that sin which we did in the past. If we aren't working to resist that evil, it stays with us and becomes part of us, until the time when we decide to make changes. Going to heaven can only occur when we are working on repentance; allowing the Lord to change our heart and save us from the evil within us.
The Lord offers forgiveness to everyone, but how that forgiveness benefits them depends upon their own response. This is illustrated in the story of the Prodigal Son. In the end, the son comes to true repentance, and finds his father's forgiveness. That doesn't seem fair to the older son, who has been faithful all along. But as the father says to the older son, "Son, you are always with me, and all that I have is yours. It was right that we should make merry and be glad, for your brother was dead and is alive again, and was lost and is found."
That's what the Lord says to us.
