What does Psalm 19:12 mean?

A close relationship with God was critically important to David. Therefore, he asks the Lord in this verse to declare him innocent of hidden faults. "Hidden faults" are sins committed in ignorance or without knowledge. The Old Testament law provided forgiveness for sins committed in ignorance. Still, Leviticus 5:17 makes it clear that whoever commits a sin unknowingly is nevertheless guilty of that sin. Numbers 15:22–29 speaks about unintentional sins and explains the procedure for forgiveness. The sacrifice of a bull was involved along with a grain offering, a drink offering, and the offering of a male goat.

Believers today, like Old Testament believers, are not expected to instantly and perfectly recognize every sin they commit. Some sins are committed unknowingly, such as accidentally saying something that hurts or insults another person. First John 1:9 assures us, "If we confess our sins, he is faithful and just to forgive us our sins and to cleanse us from all unrighteous." We do not offer a sacrifice for hidden sins because Jesus' sacrifice on the cross was sufficient to remove all our guilt.