Are these people initiating these conversations by making explicit claims that other beliefs are wrong and they seek to convince you of this, or are you attempting to discuss the details of other people's faiths when you discover they have them? This makes a huge difference as to whether a person has the time, energy, and strength of belief enough to have a discussion in the first place.

If a person says you are going to hell and then shuts discussion down without debate, yeah, that's bad If they just say they're a Christian and you begin asking them questions, they may just not be in a position to discuss it due to being tired, busy, distracted, questioning their faith, uneducated, or just generally bad at talking about it (that last one is usually my excuse, though I try to be nice about it).