@Beat, I wasn't raised in the Protestant purity culture (though I'm familiar enough with it through friends). But I was raised very Catholic, and they have their own purity culture.
Catholic "purity culture" teaches that even masturbation is a "grave sin," and the only acceptable sex is without contraception between husband and wife. Hence the giant Catholic (particularly Irish) families. It generates its own set of hangups, and fixates on the Virgin Mary's, well, virginity, as some ideal. Hell, Protestants at least allow married men, and occasionally women, to be church leaders. Only Catholicism restricts it to celibate (LOL) males. Growing up with that, I developed a lot of resentments towards Catholicism (most not related to sex). And with sex being forbidden fruit, I fell in love with strip clubs instantly. I still love the subversive elements, doubly so for buying extras, which is a different thrill from civvie dating and fucking.
Back to the original topic, most MGTOW are hostile towards religion, marriage, etc, which they regard as a restriction on male freedom. But rather, most have been burned by women and think all women just want to use and abuse men. As a result, they are resentful of just about everyone except each other. Therefore, they go on "blackpill" forums and jack each other off, or flex on Twitter about what ubermenschen they are (BTW they love Nietzsche). Either way, it's a miserable existence.
If you're doing a research project on this, you might be better served on some of those forums. MGTOW are a fairly recent phenomenon, and this forum skews older (at 41, I'm a baby next to the average TUSCLer). I'd also say forum-goers are less religious and more hedonistic than average.
Hope this helps.