"The body that is sown is perishable, it is raised imperishable" 1 Corinthians 15.42
The notion of pre-existence echoes Plato's theory of Forms, which asserts that we are born with an instinctive appreciation for beauty, harmony, virtue &c which must derive from our earlier experience of perfection. This in turn feeds into the ancient Greek insight into the distinction between an immortal soul which pre- and post- dates our earthly sojourn, for which we are equipped with a temporary physical body. Such dualistic thinking begs all sorts of questions, the most obvious being: why?
Those who airbrush God out of the picture must justify the intrusion of an atheistic meta-physical dimension into a universe which is otherwise governed by measurable properties. Believers are left wondering what is God's point in squeezing immortal souls into such unsatisfactory vessels for the brief spell of diminished existence which passes for life on earth...
While not necessarily and not in every case, religions tend nevertheless to concentrate their eternal musings on life after death: so-called subjective immortality. It is subjective because it has to do with self-awareness: the idea that those who have been resurrected continue to enjoy some form of life with is continuous with their former, mortal existence. Yet this too raises questions: What kind of shape do our resurrection "bodies" take? Is it feasible to conceive of remaining creative beings, made in the image of God, forever and ever? What will that look like and how will whatever environment we shall inhabit cope?
Christians insist that these questions, while valid, are impossible to respond to adequately because they reach for answers which are beyond our reach for the time-being. Which of course brings us back to faith - as amounting to "being sure of what we hope for and certain of what we do not see..." (Hebrews 11.1).