>everything is a test, you will never die, all you can do is hope for the best and hope those you love receive the same
I would not find it hard to take on the viewpoint that it was all for nothing or that our lives meanings were futile and useless in the face of such a dreadful existence. Played like a puppet on a string by a greater power who demands your obedience and praise. How could you not fall into nihilism being a Christian, you're the equivalent of a lab rat and even then you're not contributing to anything other than your own survival or destruction.
What does it matter if everyone is judged to heaven or hell? No lessons are learned (Well lessons are learned but there is nothing to apply them to, you simply get confirmed or denied your life then plopped into an eternal purgatory one way or the other), nothing you do really has a great effect on growing as a species or a person, the universe is destroyed accomplishing nothing in the process and that's the end of it. Where could one find meaning in an existence like that outside of their own imperative need to survive?
I don't see why theists cannot be nihilists?