See his book Guide to Rational Living.
Ellis is one of the most influential psychologists in recent years. He is the founder of the rational-emotive school of psychology and has called religion a mental disease in his writings.
From Utne Reader, March-April 1997, p. 72 (Sidebar to The Greatest Story Never Told: Researcher Dave Larson says that finding God can improve your health and he has the numbers to prove it. So why aren't more people listening?)
The Enlightened Atheist
An interview with Albert Ellis
Albert Ellis, a seminal thinker whose work on thought processes provides the foundation of cognitive psychology, is the only mental health professional to publicly rebut David Larson's work. We asked him to explain his thinking.
Q. Do you think there's a God? A. I became an atheist at 12 and still think, in all probability [voice rising], that there is no God, just as there is no Santa Claus, fairies, or angels. I found out in sixth grade that the world was created in billions of years of evolution. That knocked off my Sunday-school view that the world was created in seven days. So I said this is horseshit. And I stopped thinking about it.
Q. What about people who believe in God? A. Anybody who's an absolutist is an anti-scientist and takes things to nutty extremes. Religionists practically all do that underneath, but there are all kinds of religionists. The real bigots are off the wall, like in Iran.
Q. Isn't religion mixed with politics there? A. You're right. I think it's a basic disturbance, but of the people who have the disturbance, many more pick religion than atheism or skepticism, and religion exists because of this disturbance. Religion is just drivel