Depends on your understanding of what the concept of God is....if for example we consider Brahman...there is nothing else in existence, that's the starting point, how could anyone not accept absolute existence.... The name of absolute existence is not important, it can be called Nirvana, Tao, God, etc,...it is the one and same reality that is represented by these labels. So it is not a matter of clinging to anything, it's about letting go of all conceptual thoughts as to what is represented by 'God', and realize it directly...all else is vanity...