Psalm 14:1 Only fools say in their hearts,“There is no God.”They are corrupt, and their actions are evil; not one of them does good!
It’s also foolish to go through our day knowing God, but acting like He doesn’t exist. Failing to acknowledge our need of Jesus – going through our normal routines without actually depending upon Him or seeking His direction is foolish. When I fail to authentically seek Him and His direction – when I fail to acknowledge my dependence upon Him – I am (in a sense) acting as if God doesn’t exist. That’s foolish.