I enjoyed your post. I have a similar post titled, "Did God really declare that Atheists are fools", which arrives at the same insight as in your post, yet from a totally different perspective. You emphasized the use of the word, 'heart', that is, soul, as opposed to the word, mind in Psalms 14:1, 53:1. Absent a latching onto that dichotomy, which of course is quite insightful, but building the same argument, I arrived at a dichotomy between, 'I do not yet believe God exists', and 'Good or bad, I can do whatever I want, as such am a fool', which is essence of your post and mine. I wrote my post to make the point that hatred for Christians on the part of 'so-called atheists', hatred which they premise on the notion that they are called fools because they assert that they do not (yet) believe God exists, is premised on a misunderstanding of who exactly God calls a fool. If a so-called atheist loves his or her neighbor and reverences the notion of 'God' in the sense of being grateful for the good that is in his or her life, and is willing to engage in a search for more evidence in respect of his or her beliefs, God does not label he or she a fool. For God says, 'I love those loving me, And those seeking me earnestly do find me (Proverbs 8:17)', meaning God delights in the person who, having not yet come in contact with Him, remains open to coming in contact with Him'. My take is, we can divide so-called atheists into three camps, namely those who use, 'I do not believe God exists' as excuse for wicked living; those who will not even consider the evidence in support of the existence of God; and those who have not experienced God, as such are doubtful, but who remain open to experiencing God, who then of course necessarily are 'Agnostic' not Atheist, e.g. Albert Einstein. Clearly, the first two camps are made up of fools, because only fools either refuse to engage with evidence or attempt to live by wickedness. In stated respect, it was Albert Einstein's everyday work that convinced him of the existence of God, meaning he respected the evidence with which he came in contact, an attitude that is part essence of rationality. It is then a person's response to the everyday evidence with which he or she comes in contact that defines the person as either of a fool - who refuses to respond to evidence - or a person who desires to be wise - because wisdom is the capacity for right interpretation of things for arrival at right actions at right times. For additional concreteness, imagine a court in the USA that attempts to dispense justice without any consideration of evidence. Would make the USA the laughing stock of the world, would it not? Well then, if such a notion is foolish, a so-called atheist who will not engage with evidence in respect of his or her position acts similarly foolishly, because necessarily, the question, 'Does God exist' is an evidence based question.