True in a sense but one does not necessarily debate because they have something to prove (in the sense of personally validating themselves or justifying themselves). One also debates because words and ideas matter and they want to influence society's thinking. Because they see injustice and the erosion of freedom and want to counter it. Religious ideation harms society in certain ways and should be pushed back against to the extent that is happening.

I actually have zero problem with whatever people get up to in their private clubs, including houses of worship, so long as they don't attempt to impose their beliefs and rulesets on people outside their group. The problem with Christian fundamentalism, particularly in the US, is its unholy alliance with temporal power, and its ambition to repeal western legal systems and replace them with Old Testament law. This has been the overt goal since Rushdoony in the early 1960s and even though it's watered down and papered over with nice sounding terminology, the wet dream of Christian fundamentalism really IS something akin to the Handmaid's Tale and we're seeing it partly realized in Trumpism today. That's incredibly harmful and dangerous and I'm going to adamantly oppose it.