And no creature is hidden from his sight, but all are naked and exposed to the eyes of him to whom we must give account.
Nobody lives a truly private life. There may be things we can hide from the knowledge of other people, but nothing is ever hidden from God. Our lives are exposed as an open book before Him. He knows us intimately... good intentions, sinful twistedness, pains, and secrets... God knows each of them at all times.
I think God knows me better than I know myself. Really. I may not always remember every motivation. I may actually so justify my actions that I talk myself into actually believing that there was no wrong in a certain action. But God sees the raw, unwarped reality that is my heart. And He knows.
The scary part is that I will give account to Him for every idle word and every wicked thought. But I have a Savior and an Advocate in Jesus. That's the comforting part. I have the good news of the gospel to give me deliverance and hope. Through repentance and faith I can turn from what I don't want to be exposed as wrong, and find the righteousness of Christ applied to me. It starts with admitting my helplessness in sin. My Great High Priest lives now to intercede for me since I am totaly unable to atone this sin that I hide from humans, but is always before the eyes of God. I cannot hide from my guilt of sin, so I throw it all (guilt, confession of sin, inability to by holy) into the hands of my Redeemer.