Rom 4:8 'Blessed is the man (or woman) whom the LORD will not impute (put on your account) sin.
Every single day we live, there could be some kind of sin that is in our life, that we commit, that we omit or are ignorant of, yet God knowing these things will not impute them or put them on our record. That should make us extremely happy, because if He did put those sins on our account and charge us with sin, we would not like what happens to us because of them. So thank God and happy is that man or woman unto whom the LORD will not impute sin!
I am happy about that and have no guilt but if I sin, I must confess my sin to God and God is faithful and just to forgive me and cleanse me without imputing a single sin to me. Even if I sin (7) times in a day or more (Mt 18:22), God will not impute that sin. That is a promise from God, and God can not lie. Do you believe that?