"The fool hath said in his heart, There is no God. Corrupt are they, and have done abominable iniquity: there is none that doeth good" [Psalms 53:1, King James Version].
"The way of a fool is right in his own eyes: but he that hearkeneth unto counsel is wise" [Proverbs 12:15, op cit].
ATHEIST (definition): in the eyes of God, plainly & simply, a "fool"