Ah, so they won't be able to claim they're doing the right thing in any way?
Well, there are some who might be able to twist the texts of the religion into somehow claiming that their particular evils don't count or don't matter ("Yeah, it says not to steal, but they're choosing
to give me all this stuff after I threaten them", "Murder technically only means [oh so many choices] and what we're doing doesn't fall under that, it's not like divine law bans all killing", etc), but it really is incredibly human to not consider and internalise far-off consequences. Look at how widespread procrastination is, for example; a procrastinating student isn't unaware that they shouldn't procrastinate, but they do it anyway because oh hey I haven't read this TV Tropes page yet. And look at how humans as a whole are kinda meh on the whole environmentalism thing—not even like looking at all the facts and actually thinking we'll all be okay, but most people just don't think about it. Most people who believe in some divine afterlife reward aren't dropping everything in order to be the most charitable ever and get their rewards in heaven. These are more things of apathy, which is a lot easier than going out and murdering someone yourself, but it's realistic to just not think about what's going to happen to you later, if it's not constantly being shoved in your face now.
That's rather similar to being bad at long-term planning, I guess, but not especially so, since their afterlives might just be a specific area they don't think about a lot since it's not intrusive. People will also go through a lot of mental gymnastics to justify doing the things they're doing since it's really hard to change: it'll be okay, this fate people are warning about isn't real, oh it's real? well it's not our fault. oh, it is our fault? eh, whatever, I'm sure the next generation will figure out how to deal with it—it'll be too late by then? oh, well, what a shame, we're doomed anyway
so whatever, may as well keep acting the same way, it's too late to save ourselves...
You will not go to space today.