In an interview to Yediot Achronot (the most popular Israeli daily newspaper) which was published on June 28, 2002, acclaimed author and renowned psychiatrist Irvin D. Yalom ("The Gift Of Therapy", "When Nietzsche Wept") says the following:
Do you believe in God, in afterlife?
Would it have helped you if you'd believed?
Yes, on one hand, but it would have hurt me in other ways. In that sense that your outlook on life and your thought are actually childish.
You think that a person who believes in God is childish?
Ah... That's a tough question because it might ignite a huge fire. I've always been against organized religions, it so contradicts logic. If you believe in God, and believe in afterlife, what does it say about the other irrational beliefs? You come to believe in heaven and angels and hell and Satan and aliens, all sort of things which have no evidence, so I prefer to live in a rational world. Religion may bring comfort to people, but eventually it will bring us all down. You see what's going on all over the world. It's terrible.