Atheist opposition to religion is essentially an opposition to its truth. So it is necessary for any defence of atheism to address the challenge posed by religious belief. ‘Against religion?’ looks at the rationalisation and justification of belief in God of religious believers, describing the risk of faith and the reasoning of apologetics. The cosmological, teleological, and ontological argument are also considered before militant atheism, which makes one or both of two claims that moderate atheists do not, is discussed. The first is that religion is demonstrably false or nonsense and the second is that it is usually or always harmful.