5. The returns of varying religious founders would provide much-needed clarity on the disputed subject of religion
One of the most controversial components of human existence, religion continues to both unite and divide the various tribes of our species throughout the world. Inspiring great works of devotion and sacrifice, as well as tremendous acts of violence and hatred in the name of divine authority, the ultimate question of the universe is one that likely cannot ever be conclusively answered via rational scientific means but instead depends upon the individual logic or faith of each person. That would be unless one could converse with the founders of each world religion, to dissect and analyze their own claims firsthand.
Whilst modern scholars debate the historicity of Jesus and his miracles, of the Buddha and his conversion from Siddhartha Gautama to a religious leader, or of Mohammad and the divine revelation he supposedly received in the Cave of Hira, these inquiries can be far more definitively answered via the specific individuals in question. Resulting in either the unification of humanity under a single banner of one true religion following recorded demonstration of the divine, or the death knell of religion and the emergence of humanity into an age of secular reason, one cannot deny the rationality nor usefulness of bringing such people back from the dead.