Interesting to see an old Molyneux video still on the YouBoobs.
I've seen this interaction. Back around 2010 at an atheist meetup in Cincinnati, one of the people there was a super libertarian and said "Taxation was theft." I wouldn't say the other atheists 'religiously defended the state,' but many of them did push back on the guy, and didn't agree with "taxation is theft"
However, his claim that most Christians will leave you alone ... well, individualism is distinctly part of American Christianity. It's not seen in other Christian contexts, and for a lot of history, Christianity and the State were intrinsically linked. The "body of Christ is the Church" is a collectivist concept. The idea of the King, the Church and the Court (or in America, the checks and balances of the three branches) directly related to the concepts of a trinity.
I'm also not sure about this entire "population collapse," message. Louise Perry brings it up in her podcast a lot; how the elderly will depend on the welfare paid for by taxing the young. I've seen it from her and other conservatives, right next to the dangers of Internet porn, social media and the sexual revolution ... lots of moral panic.
I do think if you don't have kids, it might be wise to save up a lot and face the reality being old in this era might be rough. But the population is going to decline no matter what. It will rise again too. It's inevitable. Trying to encourage more children to prevent collapse seems just as stupid as China's one-child policy. If you want kids, have kids. If you don't want kids, don't have kids. Don't scream at someone for having 5 kids.
If people are free to make their own choices, things will eventually balance out. The path might be challenging and people might suffer along the way, but that's the human condition.