It would be a contradiction in terms and ontology if God could lie, and therefore it's impossible.

1. God is ideally definable as the ideal being, greater than any other imaginable being, and perfect in his attributes. Therefore if God could lie, he could not be God, and so a self-defeating and self-contradictory proposition.

2. Without truth, there is no morality. Without morality, there is no goodness or right/wrong. Without the possibilities of truth, goodness, or right, there can be no God. It goes against every reasonable and acceptable definition of God.

3. The Liar's Paradox ([url]https://en.wikipedia.org/wiki/Liar_paradox[/url]) shows that if God is a liar, he is a living ontological contradiction, which is logically impossible. A cannot equal non-A.

Just as a forward here I am an atheist just trying to gain a broader perspective.

I'm curious how one can be sure that god is incapable of lying. I feel as if Christians would immediately look to the Bible for verses explaining god's inability to lie. This seems like somewhat of a conflict of interest however. The Bible is the direct word if god. You can't find out if something can lie by looking to its own words. Is there some sort of third party or independent source that Christians can look to to know that god can not lie?