That’s just a silly argument Europe has negative population growth. Have you been there? Have you lived there? Spoken the local language? They not only have no marriage, no church going and no regard for God they have disdain for these entities and for everyone involved in them
They are being completely over run while in denial. They have no will and no manner in which to stop the takeover of their church buildings, their progeny and their land by the Muslims.
That’s from birth control
It's all hypothetical, as I said. Right now the problem is too much birth control. I only intend to give a counterexample, one which has manifest itself in many places.
This isn't necessarily a defense of the birth control pill. Dangerously fast population growth can also be controlled by changes in family formation - later marriage for women being the most effective.
Remember, these methods were used in Europe when it was 100% Christian. That's why Europe suffered less starvation than Asia, which didn't limit family size as much.