In the scenario that some sort of spirit told me, I would probably be strangely reassured knowing that there is a life after death when my whole life I have strongly doubted the matter.

I do not wish to be vindicated in death, I hope with all my heart that I am wrong, and that there is in fact an afterlife. I don't wanna stop existing.

I would go talk to my friends, and tell them I know that there is SOMETHING else out there. Then, I don't know.