And if a soul sin, and commit any of these things which are forbidden to be done by the commandments of the LORD; though he wist it not, yet is he guilty, and shall bear his iniquity.  And he shall bring a ram without blemish out of the flock, with thy estimation, for a trespass offering, unto the priest: and the priest shall make an atonement for him concerning his ignorance wherein he erred and wist it not, and it shall be forgiven him.  It is a trespass offering: he hath certainly trespassed against the LORD.
Leviticus 5:17-19

There are sins and transgressions we commit against God that are still sins, yet they are not willful acts of sin. Yet, even these are  sins that we must seek God’s forgiveness.

That forgiveness is also through the death, burial, and resurrection of Jesus Christ. His life’s blood cleanses us from all sin.