'Liar' in the Bible

You are of your father the devil, and it is your will to practice the desires [which are characteristic] of your father. He was a murderer from the beginning, and does not stand in the truth because there is no truth in him. When he lies, he speaks what is natural to him, for he is a liar and the father of lies and half-truths.

Yet you do not know Him, but I know Him fully. If I said I did not know Him, I would be a liar like you. But I do know Him and keep His word.