Metaphysically impersonal first cause is a good way to capture the essence of God in nondualism. Most atheists are reacting to God presented in anthropomorphic terms. Because that has caused so much division, conflict, wars etc. If, on the other hand, the impersonal principle which is pure consciousness is presented in the right manner logically, then we may not see the same resistance from most atheists - who are ready and open to inquire. And the hard problem will be solved too. I have talked about the hard problem and how nondualism neatly resolves it in this article:

https://sureshn13.medium.com/the-hard-problem-of-consciousness-325d212fbced