I haven't always given full repentance, yet he forgave me over and over.
Matthew 18:21-22 ~ 21 Then Peter came to Jesus and asked, "Lord, how many times shall I forgive my brother when he sins against me? Up to seven times?" 22 Jesus answered, "I tell you, not seven times, but seventy-seven times.
I used to be involved in pornography heavily, for a long time. I knew from an early age that it was wrong, but I couldn't stop, I just kept going "back to the bottle". There were times where God would directly discipline me, and there were times where He just let it slide and bless me. I had not fully repented of it in those decades. I tried, but never did.
It wasn't until very recently where I kicked the addiction, by God's grace and power. Not only did he prevent me from looking at it when times were rough, but He gave me His law that I've hidden in my heart that I might not sin against Him. He gave me His wisdom, so that I would learn about the wicked adulteress in Proverbs 2, 5, 6, and 7, and also who wisdom is... that she fears the Lord and to fear the Lord is to hate evil (Pro 8:13).
And lots of prayer by me and those who keep me accountable. I'm still repenting of it, it's a struggle, but I've never had this freedom before, and it's so good.
But why was I forgiven? I was forgiven, not because I repented, as I kept going back and still struggle in my thoughts with this area. I was forgiven on the basis of the atonement that Jesus made when he became the sacrifice for sins.
If it were on the basis of repentance, I wouldn't be forgiven, and nobody would because we all sin in many ways, even in ways we don't know (as has been pointed out to me here). My only hope is found in Jesus. Before God, I'm guilty and deserve his wrath.