One reason that nearly all the Christian churches are falling (or already fallen) to the (evil) secular, Left anti-Christian agenda; is that these churches usually believed (often as a matter of faith, a dogma) that their churches were (essentially) supernatural, eternal divine persons that could not be corrupted.
They believed that although individual humans who worked in the church institutions could be corrupted - the essence of the church was a supernaturally validated and defended entity that was invulnerable to corruption.
By contrast, the mainstream socio-political Left believed that institutions are human creations inhabited by humans (this including churches and also all corporations, industries, professions, sciences, societies, unions, charities, newspapers and media, schools and colleges, hospitals... all institutions of all kinds).
And as such, all institutions could (in principle) be corrupted: could be subverted, destroyed, inverted... could be 'hollowed-out and worn as a skin-suit'; could be co-opted and redirected to serve to the (anti-Christian) Left agenda; no matter what they had originally been, no matter what their original purpose.
Even when that institution had been doing some other thing for hundreds of years - like some churches and colleges and professions like Law and Medicine - the Left believed that by replacement of personnel and by new managererialism they could all be made servants of the Left agenda.
They were correct!
So we see all institutions of all kinds - including Christian churches - increasingly-completely sharing the primary Leftist goals such as equality, feminism, antiracism and diversity, the climate emergency agenda, and active promotion of the sexual revolution (coercively, aggressively, with no opposition nor opt-outs allowed).
Religious denominations were wrong, and are wrong, if they suppose that God operates to immunise certain belief-systems against Leftism.
There is zero positve evidence for that assumption and massive counter-evidence..; although any church is, of course, free to insist: "but that was them - it couldn't happen to us." - just so long as they aware that all the other churches said exactly the same thing at some point.
Yet Just Look At Them, Now!
What I am saying is that institutions are not like individual human beings, and even less like supernatural, eternal divine persons: on the contrary, an institution is (over the long term) nothing more than the people running it and the system that they follow.
Replace the people and change the system (by changing the rules, or changing the way people interpret the rules) and you get a different institution. Often a completely different institution; sharing nothing but the name and lineal continuity with what was before.
An institution may begin as a Christian church, or a college, or a science, or a news agency, or a charity to provide food to the poor... but by the time the people and the rules have been replaced; it will end-up as just another Leftist, Generic, Bureaucratic, Totalitarian, Managerial System - doing what all the other LGBTMSs are doing - including the pursuit of plans and policies motivated by strategic anti-Christian animus.