Souls being immortal vs all of existence needing to be continually and actively maintained by God

Non Christian asking a question here. My understanding is that Christianity claims that: A) Souls are immortal. B) Everything that exists (except God Himself) needs to be continually maintained by God, or it'll simply disappear. This seems to me to be contradictory. Assuming souls are not an exception to the above rule, it seems to me that immortality means that something will exist as long as God sees fit to maintain it. My problem with this is that surely God can maintain anything indefinitely, so there's nothing special about Souls. God could maintain a speck of dust indefinitely, say. One could say that souls being immortal isn't an inherent trait, but a prediction of sorts. It's not that souls *can* exist forever that makes them special; it's that they *will* exist forever. However, I've yet to see any Christian argue for this view. Regards, Peter.