From a quote in an article on the Catholic nature of LOTR comes a gem from Tolkien explaining what hope is and succinctly describes the source for a Christians hope. The scene the passage refers to is that of Aragorn’s death, when Arwen calls Aragorn by his true name, Estel.
This scene is illuminated by a remarkable dialogue about death between the High Elf King Finrod and the human woman Andreth. The dialogue goes back to very early times, before the story of Beren and Luthien, the ancient pattern of the story of Aragorn and Arwen. Andreth loves an Elf, Finrod’s brother, who loves her in return. It becomes clear to Andreth that she will grow old and die, while her beloved remains young and free from death. The realization leads her to despair. “‘Have ye then no hope (in the face of death)?’ said Finrod. ‘What is hope?’ Andreth said. ‘An expectation of good, which though uncertain has some foundation in what is known? Then we have none.’ ‘That is one thing that men call “hope”,’ said Finrod. ‘Amdir we call it. But there is another which is founded deeper. Estel we call it, that is “trust.” It is not defeated by the ways of the world, for it does not come from experience, but from our nature and first being. If we are indeed the Eruhin, the Children of the One, then He will not suffer himself to be deprived of His own, not by any Enemy, not even by ourselves. This is the last foundation of Estel, which we keep even when we contemplate the End: of all his designs the issue must be for His Children’s joy.'”
Emphasis was added by myself.