Teshuva (repentance) means to come back to the greatness which is expected of us, even if you did not do any sins at all. Did you learn enough Torah? Did you love Hashem enough? Did you think about His greatness enough? Did you do kindness to your fellow man enough? So many things to do! Teshuva means to come back to perfection, not merely to stop doing sins. ~ R’ Avigdor Miller zt”l