How do we know God is omniscient?

God's omniscience, or all-knowing nature, is depicted in various biblical passages. In Psalm 139, we are reminded that God is intimately aware of every action and thought, asserting that He knows us even before we were formed in the womb. Additionally, Ephesians 1 describes how God chose and predestined us before the foundation of the world, highlighting His comprehensive foreknowledge. This attribute comforts believers, knowing that God’s understanding surpasses human comprehension, as expressed in 1 John 3:18-20 where it directly states that God is greater than our hearts and knows all things.