'Liar' in the Bible

You are of your father the Devil, and you want to carry out your father’s desires. He was a murderer from the beginning and has not stood in the truth, because there is no truth in him. When he tells a lie, he speaks from his own nature, because he is a liar and the father of liars.

You’ve never known Him, but I know Him. If I were to say I don’t know Him, I would be a liar like you. But I do know Him, and I keep His word.