I think it's not necessary the life elements to come from the space, because that time the Earth was something like the comets now (without air, without life, with a lot of radiation, etc.) And
even the life's elements (or some of them) came from the space, it's not a valid argument that they're 'Made in God-land'.
The opposite -- it's a serious issue for those, who believe the religions, that postulate that God created the Universe (everything) in 6 days.
If the Alien life form seeded the galaxy with life, then it's again, not an argument that this Alien life was God-made.
I never thought that it's an interesting question (where exactly the life began/begins -- on Earth, on a comet or somewhere else). For me the most interesting question is how exactly it began/begins and what's its real essence + how to fight the death.