Real, true repentance is being sorry for our sin, sorry enough for it to change our heart and our direction with God's help. The moment we trust in Christ we are forgiven every sin and made righteous, in right standing with God. From that point, God sees us in Christ, washed in His blood.
So we are not righteous because of what we do, but because of what He has done – if we put our trust in Him. In that position of righteousness we are empowered to choose the right things, do the right things, and live the right way.