I grew up in a very Catholic household. I'm agnostic now, but those closest to me believe in God, and I respect that.
I have a friend who I'm very close to who is also very Christian. We haven't broached the subject of religion very often on more than a superficial level. Part of that is because both of us knew without saying anything that it wouldn't go well (we discussed that a while back).
Since her faith is a big part of who she is, I'd like to be able to have conversations with her about it. It's hard to do so when we look at the world so differently. Every problem is solved with God and the Bible for her. Nothing that I bring forth - be it scientific or an argument about the Bible - can change her viewpoints because our worldviews have such different origins.
Both of us end up irritated, and I end up feeling like she doesn't respect my opinions.
For a specific example, we had a discussion today about the first letter of John that she had sent to me recently. I had some thoughts about it contradicting itself and the rest of the Bible. She explained why it didn't, and I said I'd let her know if I agreed after I finished reading the letter. She claimed that I would have to read more than just the letter, and I responded that I grew up Catholic and have read large amounts of the Bible because of that. She said that's true, but even though I believed, I had no "living faith". That devolved into an argument about whether or not that was true, which ended with both of us being frustrated and me getting angry and then feeling guilty about getting angry (I didn't yell at her, but I did express my frustration). She maintained through the whole argument that I didn't understand what she was saying.
This would probably be similar in person, but it may be important information to note that this was over text.
An example of the "because God" arguments I'm referencing were from a separate conversation about cloning. My first example didn't have them from what I can tell. Her belief was that cloned humans aren't really humans because they don't have a spirit. It's frustrating to be unable to argue against that, but that didn't cause the rift that the discussion above caused (at least from my point of view).
How can I discuss parts of the Bible / Christianity with her without both of us getting frustrated and irritated at each other?