I worked in full-time Christian ministry for 6 years. I understand where your friend is coming from and there is little you can do for them other than love them and maybe teach them logical fallacies and common cognitive biases. From there, they may reject God/Spirit/etc entirely and then from there may travel through a Hero's journey back to an understanding of God again.

Or something like that. :) In this life experience or another.

Ultimately, what matters is love. When people feel genuine love (unity) without conditions, they feel God and experience truth.