God knows the secrets of the heart; there are no parts you can hide from Him.
"If we had forgotten the name of our God or spread out our hands to a foreign god, would not God discover this? For he knows the secrets of the heart." - Psalm 44:20–21
Does your heart condemn you with guilt, shame, or malice? Thankfully, God's understanding of us is greater than what others or even we believe about ourselves.
"By this we shall know that we are of the truth and reassure our heart before him; for whenever our heart condemns us, God is greater than our heart, and he knows everything." - 1 John 3:19–20
Did you know that you were known by God as long as He has existed? And for those in Christ, He has loved you for all eternity—past, present, and into the future.
"For those whom he foreknew he also predestined to be conformed to the image of his Son, in order that he might be the firstborn among many brothers." - Romans 8:29
The omniscience of God can be a terrifying reality, but also one of the most comforting truths of His character. He who knows us the best, loves us the most.
"O LORD, you have searched me and known me! You know when I sit down and when I rise up; you discern my thoughts from afar." - Psalm 139:1–2