“Nothing in all creation is hidden from God’s sight. Everything is uncovered and laid bare before the eyes of him to whom we must give account.” Hebrews 4:13
To me, this verse means exactly what it says: God knows everything, and nothing is hidden from his sight. This verse is a reminder for us. Whenever we are tempted into doing things that aren’t right because “no one will see” or “no one will know,” this verse is there to tell us that actually, God sees and God knows.
The verse also says that “everything is laid bare and uncovered before the eyes of him.” This part says that when you do something, God sees the true intention of why you did it. For example, if you lie to your parents about something, God knows that you lied, even if your parents didn’t. This verse is telling us that everything we do is known by God, hence Psalm 139:2: “You know when I sit and when I rise; you perceive my thoughts from afar.”