If the atheist is correct, meaning god never existed, the religious individual has suffered for their religious believes for no reason. In other words, the 'believer' has lived a lie. What the religious individual fails to understand is the fact that every 'true believer' has atheistic tendencies. This is derived from the religious individual's active rejection of a particular god or set of gods. Examine the religions of Christianity, Islam, and Judaism from another stand point.
Christians are atheists to the Roman gods.
Muslims are atheists to the Hindu gods. Jews are atheists to the Norse gods. The point of this matter is that the 'true believer' actively rejects all the gods that are not their own. An atheist has rejected the concept of god and actively proclaims that 'god' never existed in the first place. A person whose attitudes and behavior are marked by conformity to the standards and conventions of the middle class.