If God did not exist, it would be necessary to invent him.
Voltaire (1694-1778) 

If God does not exist, then everything is permitted.
Fyodor Dostoevsky  - The Devils

If you are going to sin, sin against God, not the bureaucracy. God will forgive you but the bureaucracy won't.
Hyman Rickover 

If you talk to God, you are praying; if God talks to you, you have schizophrenia.
Thomas Szasz 

In every country and every age, the priest has been hostile to Liberty.
Thomas Jefferson (1743-1826) 

It is always right that a man should be able to render a reason for the faith that is within him.
Sydney Smith 

It is the final proof of God's omnipotence that he need not exist in order to save us.
Peter de Vries 

It was the experience of mystery - even if mixed with fear - that engendered religion.
Albert Einstein (1879-1955) 

Mathematics transfigures the fortuitous concourse of atoms into the tracery of the finger of God.
Herbert Westren Turnbull 

Matters of religion should never be matters of controversy. We neither argue with a lover about his taste, not condemn him, if we are just, for knowing so human a passion.
George Santayana (1863-1952)