here that Philosophy and Literature would make a good combined University degree course. Novels are about people and people have beliefs so sometimes we engage with fiction by discussing beliefs. Poul Anderson's characters address and discuss their own and each other's beliefs:
Peter Berg's experience with the Ythrians makes him question his Church's response to the theological problem of pain;
Aycharaych asks whether mortality is necessary for human creativity;
Dominic Flandry addresses/prays to his murdered fiancee, the future St Kossara, while she lies in the Cathedral where she had been confirmed and they would have been married;
Nicholas van Rijn leaves it to the theologians to rule on whether aliens have souls - that is what they are paid to do.
SM Stirling's Juniper Mackenzie thinks:
"...we are right to fear [death], for it is dreadful to pass through the dark gate, even if you know what waits beyond."
-SM Stirling, The Scourge Of God (New York, 2009), Chapter Four, p. 121.
No one knows! How can anyone make such a claim? Death is:
"The undiscovered country from whose bourn
"No traveler returns..." (see here and here)
Only the Spiritualists claim direct contact with the hereafter but they have not proved their case and their account differs from that of the Wiccans, including Juniper. We did not call it "knowledge" when some said that trans-Atlantic sailors would reach Asia whereas others said that they would fall off the Earth and no one had yet been there to find out. I am permanently amazed at unquestioning acceptance of different versions of a hereafter.