'Liar' in the Bible

You are of your father, the devil, and you want to do the desires of your father. He was a murderer from the beginning, and doesn't stand in the truth, because there is no truth in him. When he speaks a lie, he speaks on his own; for he is a liar, and its father.

You have not known him, but I know him. If I said, 'I don't know him,' I would be like you, a liar. But I know him, and keep his word.