Lack of belief in an immortal soul
..does not imply that you are not Christian. Especially as none of the 1st Century Christians believed in immortal souls - it was an idea that got implanted into the early church from pagan beliefs.
Much like the concept of a trinity. And a literal devil. None are in Biblical Christianity. And, as a Christian myself, I don't believe in an immortal soul - the biblical hope is resurrection.
(Yes, I know that theology isn't likely to be a core skill round here but I thought it worth mentioning)