The Christian concept of God certainly can be understood the way I am speaking. It may not be the most commonly spoken of view of the Divine, but it certainly does exist within it. What is taught in Sunday School, is not the the measure of the breadth, height, and depth of understanding God within Christianity. Those are really more "introductory" or "training wheels" ways to begin to approach an understanding of the Divine. Christianity can certainly go beyond that, and does for those wishing to understand more than a literalist, externalized God interpretation.
"Post-death" is really irrelevant. "Eternal life", can easily be understood as the timeless present. It is about "this life", not after one dies. IMO, after one dies is meaningless. What you are in the moment is the only meaning. And if someone postpones, or better stated avoids facing Reality in this life, they won't have it in the next, in whatever form that takes. I view Life, as one thing, not just the animation of our present biological form.
Now as far as "believing in God in order to not be in a hell-state", I disagree. Beliefs are conceptual. They are thoughts, and ideas. What we "think" is irrelevant to having a connection with Reality. That connection is based upon our presence of being. It is a connection with our subjective self with the world, and who we authentically are. Thoughts and ideas come and go, change and evolve, like the leaves on a tree in the course of a season of growth. But the roots and the trunk is our connection. Those just deepen and strengthen. Being rooted and grounded, is not a matter of our conceptual minds. That is a matter of our being itself, or to use a Christian metaphor here, our "soul".
An atheist can have just as much connection with Reality as a believer in a particular deity form can. In fact, the greatest depths occur when we are able to move beyond even our religious ideas and beliefs. The great Christian mystic Meister Eckhart said paradoxically, "I pray God make me free from God, so that I may know God in his unconditioned being". That means, drop your beliefs. They get in the way. In this sense, a spiritual atheist, may actually be in a position of greater advantage, because he has already deconstructed religious beliefs. But if he imposes a "scientific belief" instead as ultimate Truth, then he is disadvantaged the same as the ardent "believer" in religious views.
Functionally, these different understandings of hell are very different. The traditionalist view which images hell as a "place" makes it external to oneself. The metaphoric view of hell makes it internal or subjective to ones experience. To look outside oneself to find oneself, is doomed to failure. To look within, is the path to Awakening. All traditions teach this, once you move beyond the externalized God.