When children lie parents sometimes tend to treat the problem as one of logic and intelligence; they puzzle over why their children would lie. Scripture solves the mystery. Humans are born liars. When we sin, we lose the ability to be logical. We are blinded by self-interest (Proverbs 4:19; Psalm 58:3). Lying is the extension of a self-centered nature. Children tend to lie in two types of circumstances. First, they lie when they fear a consequence so much they will do anything to avoid it, e.g., punishment for hitting. Second, children tend to lie when there is something they desire, and they see lying as the best way to get it. In both situations the reason for the lie is the same — a self-centered heart.
Children lie because they fear exposure. They think their thoughts and doubts are hidden, and a lie is the best way to solve the problem. However, nothing is hidden from God.