They have plenty of justification from their p.o.v. because *if* their beliefs are true, then what they are doing is morally right. It's as if they see a child drowning at the beach, so they feel *compelled* to save them. But someone could come along and point out that they're in fact just practising butterfly which makes it look as if they're drowning, because they're not very good at it 
Of course, the big question is obviously whether their beliefs are in fact true.
Of course, the big question is obviously whether their beliefs are in fact true.
"It is the mark of an educated mind to be able to entertain a thought without accepting it" ~ Aristotle
