My religion has taught me there was alien life since I was a child. I was also taught that all humans and all animal life will be resurrected. It's not too hard to extrapolate that intelligent alien species, should they exist, would as well. So maybe the answer to your question is "It depends on the religion."
I'm Mormon (or more pedantically I'm a member of the Church of Jesus Christ of Latter-Day Saints) so kbutler caught me.
He's quoting from the Doctrine & Covenants (like the Pauline epistles in that they're letters written by someone claiming to speak messages from God, but not like them in that they were written in the 1830s and 40s in America) and it's this more modern scripture that tends to talk about these kind of things. Basically any decent religion will start out with "Be nice to your neighbors" but when you start asking "Why?" it is inevitable going to end up in a discussion about the nature of the universe and its the modern scripture that tends to crystallize that a bit.
And for the record, "alien life" in Mormonism means other earths very similiar to the one we inhabit, populated by people like the people that live here on our earth. Not usually what most people think of when they hear of aliens.
