Okay, so… how?
Traditional religious institutions, such as churches, were a central focus in people’s lives, and often the primary location for people to meet and socialize after a long week of backbreaking work. Today, most people have other, generally far more suitable options.
They were also seen as places of comfort, safety, and a refuge from having to deal with a barely comprehensible world. Today, most people have far better options for comfort, know that the “safety” of the church is largely an illusion, that some may even be in danger from the church itself (which has always been true, but not attending may often have been the greater danger), and on the average are far less ignorant and can make connections with (hopefully trustworthy) others who can cover for the areas where you personally are ignorant, so the world is far easier to deal with.
In the countries where the majority religion is Christianity (or none at all) there is no longer separate “Royal Law” and “Ecclesiastical Law” where the latter is something the common people were more likely to run afoul of. There is only secular law (or dictatorial law, in the case of a handful of Central American and African countries), which may be influenced by the religious beliefs of the general population, but the churches have very limited power and no control over it.
The churches which are hemorrhaging members the fastest are the ones which promote various bigotries. Gen Z, despite apparently being a bit less liberal as a whole than Millennials, really don’t care for that. You might get a few who feel that their peers are brutalizing them just because they insist “women can’t be men” or “black people are crimers, it’s just science” or incel-shaming them for even rather basic misogyny, or whatever, but that’s a rather small minority.
Bringing most of Gen Z into the fold would require some rather radical changes, likely to the point where “traditional institutions” completely drop the “traditional” part. Which I suspect you would never do, due to considering such a thing he hollowest and/or most pyrrhic of victories. The other option would be to institute a brutal theocracy, but given that very few Millennials or Gen Z would care for that cause, Gen X and Boomers really wouldn’t care for the disruption to their lives even if they supported it in the abstract, and the older generations are dying off rapidly… one year is delusionally optimistic, to put it mildly.
