I think this deserves a serious answer:
The reason that I think the very first poster on this thread commented on your premedical status is that premeds (like most people who haven't been through it) tend to think that medical training is more spiritually challenging than it really is. The feeling is that medicine, like a mission trip, or a war, or maybe just a really good social sciences class, forces you to confront a part of reality that we normally try very hard not to look at. The theory goes that you thereby must necessarily change in a fundamental way as you try and reconclile your beliefs with what you now can't help seeing. It's a common view, and one that is very played up on film and television.
But the reality, at least for me, honestly isn't like that. Modern medicine is very sanitized and very compartmentalized. You see very small portions of your patients' care, very small parts of their tragedies. The ones you connect with on a human level you never see get really sick, or if they do go downhill they get passed off to a specialist long before things get bad, and when things get even worse the specialist passes them off to an intensivist, or surgeon, or hospice. And if you are the intensivist or the surgeon the patient doesn't really register in the same way. They don't talk, they're not conscious, they turn into a bundle of lab values and treatments. Not something that you cry over.
And even when you do get to see the degeneration/death of a patient who you actually knew when they could communicate, it's still very sanitized. As a general rule if you're in the hospital we're going to make sure that you at least don't LOOK like you're suffering. There is very little blood on the floor, small surgical fields, little crying, almost no screaming. There are grief specialists to handle the grief, and even the physicians' brief contact with that NEVER involves the medical student. And when all else fails there's just the fact that we don't spend very much time with individual patients. I just don't feel a hole in my life because something tragic happend to someone who I've had less than an hour of actual contact with. I'm not a cold hearted person, but like most people I need to have some sort of a real human connection to feel a loss. The times I've lost family members, or even family pets, went much farther towards advancing my religious beliefs than everything I've seen in medicine put together.
From my cadavar onwards medicine has been full of things that I consciously know ought to have moved me, but which just haven't. They were too removed from me, and often didn't have enough humanity left to connect with. Maybe it will be different when I'm in Pediatrics. Maybe neonatologists and Peds Heme/onc specialists, who see children fade away over the course of months or even years, might have their faith affected by their professions. Honestly a big part of the reason I'm going into Peds is because those are some of the only patients that I felt like I both connected to and could help (normally its one or the other, if either). Until then, though, I just don't think that medicine is visceral enough to really change or challenge my views on God, spirituality, or the nature of existence. No more than those beliefs would naturally change with introspection and time.