Was Aleister Crowley an atheist

Answer 1

He was Christian, but he looked for alternatives.

Answer #2.

The centrepiece of his philosophy is a tripartite division of the Universe;

1. 'Nuit', extended space, the Universe as we perceive it,

2. 'Hadit', the point origin, Monad;

3. 'Ra-Hoor-Khuit' the active, creative power connecting them.

Although these names are derived from the Egyptian religion, Crowley used the doctrines of many religions to demonstrate the unity behind them, or to highlight particular differences. The Thelemite (a follower of the philosophy) lives as the manifestation of Ra-Hoor-Khuit, or Reharakhti. The Law of the Thelemite, 'Do What Thou Wilt', is not a licence, but the severest discipline possible to impose upon oneself.