Psalm 14:1 defines a fool as someone who says there is no God. What do you suppose that kind of perspective looks like when it shows up in a court of law? What is really being said by a witness when they're asked to raise their hand and swear to, "...tell the truth, the whole truth and nothing but the truth, so help you God?" If there is no absolute apart from themselves, what they're really saying is, "I'll tell you what I want, how I feel, and I don't care if it's right because it's all about me."