The alternative about existence or not existence of a creator god cannot be decided by the argument of the first cause.

Who argues, that a first cause is needed and that this first cause is god, has to answer the question:

Was is the cause of the creator god?

The alternative between existence and non-existence of a creator god cannot be decided by the argument of the first cause.

Whoever argues that a first cause is needed and that this first cause is god, has to answer the question:

What is the cause of the creator god?