Secret sins are not so secret. Sexual immorality (pornography, adultery, homosexuality, lusting, etc.), eating disorders, lying, hating, unforgiveness, envy, jealousy, stealing and deceit are examples of secret sins.

God knows what has transpired, so it is not so secret.

“You have set our iniquities before You, Our secret sins in the light of Your countenance.” Psalm 90:8

God will bring to light the things that are not of Him. We are responsible for confessing our sins and not walking in them ever again.