Patrick is not religious, the fact that he turns to god in a moment of extreme despair changes nothing. in the face of death it is full of believers
DPC, rightly, doesn't give him all that much space but it is significant that as long as Helen is still healthy Patrick in no way appears religious, indeed he prefers her to do the praying at lunch, because it is not his thing.
Then everything falls apart and Patrick hopes Helen was right about God, but it is a reflex faith, not his.
and it is also very likely that his 'homophobia' is all about the issue of grandchildren to be brought to Helen as soon as possible, a mission for which Maya's 'phase' is an obstacle.