"What if" is a symptom of unknowing and concomitant fear of human ego's disappearance. Rest assured there is God, eternal hope for the soul and her progress, and plenty of heavenly assistance.
However, in the great foreverness of becoming a permanent Atom of Being in the Body or Spirit of God, whether one considers one's whole life, or even the "string of pearls" that constitute a lifestream's series of incarnations, these are quite minimal, in terms of the eternality of Being which finds perfected lifestreams moving in the reality of God, Truth.
So, if this is all there is, i.e., no God, no Soul-individuation (e.g., Moses, Jesus, Mohammad (owbp), Sri Ramakrishna and Saint Therese of Lisieux were all naive, self-deceived idealists), then passing on is as going to a good night's rest, a deep, dreamless sleep. In that hypothetical, it is agnostically and Pascalianly valid to entertain a "what if" hope of a) what dreams may come, b) an increasing movement from less light to more Light, and c) a soul-awakening in schools of Light, with guidance therewith proceeding. One's mindset and emotions just prior to sleep and also prior to passing on are keys to more rapid alertness and ability to transcend lower aspects or mundane entanglings. Thus, a correct philosophical attitude re both 'what dreams may come" and also "what resurrection may come" is: hopeful, wait-and-see; if Jesus simply went to sleep, like Saint Lazarus, and neither were awakened or resurrected, then going to sleep or passing on is simply a closing of a book, "The End." Alternatively, if one is to believe e.g. the Ascension of Elijah, the night-flight of Mohammad (pbuh), etc. then it is logical for the "philosopher" to be open, even proactive, re sleeping-soul learning, and passing on-soul awakening. That soul-learning occurs during sleep is scientific fact, hence proactive intention to be directed by God/higher power includes the mere lucidity of the more integrated human psyche, but, for the honest agnostic, also openness to the possible existence of legions of Angels (Ideas of God, Mind), Teachers of Light, and so on. For such, "Truth" is the coin of the realm.
Related:
Men in White Apparel;
The Undiscovered Country by Easwaren;
The Path of the Higher Self;
Light Is a Living Spirit;
Testimony of Light;
The Great Divorce.