I don't think you get "an insane amount of xp" for building the church, as it's been said here. You take what you deserve. The experience rises along with the church level so it takes many hours of building to get to the 2k-3k xp, which come fom 90-100+ lvl churches.
If you have the merit or luck of being in a town with a church that evolved, then cheers, enjoy it. If you don't, either work for it or stop whining over those who do.
your kidding right? watch dakota they get 2k or even more xp on level 50 churches already and as level 60-70 pure construction, getting a church that high isn't exactly such a challenge as well it takes a few people building a few days.
Now in all honestly you don't think church construction xp is a tad high seeing on dakota(a new world!!) people get 40-50k xp a day where even if you do 12 2 hours hold jobs you might get 15k xp (not to mention skilling to do those jobs is a pain and can't be reached easiest + you need to find em gold which they aren't often) its totally unbalanced, try to see how many quests you need to complete to get such an amount of xp.
And it has nothing to do with luck being in such a town, just have high construction and ask an invite and you will be accepted, since the more workers the faster the church level rises
IMO i really hope the devs will cap building xp since atm its just nonsense how fast you can level with it, or you think its normal you can go level 90 to 93 in a day? maybe check the hall of fame on older worlds, and see how long people did for the steps level 80 to 100 and 100 to 120, you will see that beeing to able to do those steps in 1-2 weeks is really really fast compared with the previous situation(just an example on colorado the first person to reach level 80 took more then a month to reach level 100 and almost 2 months to reach level 120, on dakota world is not even 2 months old and within a week we will already have the first level 100s due to that building)