I recall reading, in the past, about a philosopher who acknowledged that the existence of God was completely irrational and that he probably didn't exist. However, he emphasized that despite this fact, people should and need to believe in religion to feel happy, moral, and fulfilled in life, and so, belief is necessary. I can't recall who this is although I'm leaning towards Kant or Aristotle. Do you know who I can attribute this idea to or where I can read more?