Christianity in Middle-earth in the context of "Death and immortality in Middle-earth"

In J. R. R. Tolkien's legendarium, the history of Arda, also called the history of Middle-earth, began when the Ainur entered Arda, following the creation events in the Ainulindalë and long ages of labour throughout Eä, the fictional universe. Time from that point was measured using Valian Years, though the subsequent history of Arda was divided into three time periods using different years, known as the Years of the Lamps, the Years of the Trees, and the Years of the Sun. A separate, overlapping chronology divides the history into 'Ages of the Children of Ilúvatar'. The first such Age began with the Awakening of the Elves during the Years of the Trees and continued for the first six centuries of the Years of the Sun. All the subsequent Ages took place during the Years of the Sun. Most Middle-earth stories take place in the first three Ages of the Children of Ilúvatar.

Major themes of the history are the divine creation of the world, followed by the splintering of the created light as different wills come into conflict. Scholars have noted the biblical echoes of God, Satan, and the fall of man here, rooted in Tolkien's own Christian faith. Arda is, as critics have noted, "our own green and solid Earth at some quite remote epoch in the past." As such, it has not only an immediate story but a history, and the whole thing is an "imagined prehistory" of the Earth as it is now.

The Ainulindalë (Quenya: [ˌai̯nuˈlindalɛ]; "Music of the Ainur") is the creation account in J. R. R. Tolkien's legendarium, published posthumously as the first part of The Silmarillion in 1977. The Ainulindalë sets out a central part of the cosmology of Tolkien's legendarium, telling how the Ainur, a class of angelic beings, perform a great music prefiguring the creation of the material universe, Eä, including Middle-Earth.The creator Eru Ilúvatar introduces the theme of the sentient races of Elves and Men, not anticipated by the Ainur, and gives physical being to the prefigured universe. Some of the Ainur decide to enter the physical world to prepare for their arrival, becoming the Valar and Maiar.

Tolkien wrote the initial version of the Ainulindalë between November 1919 and the spring of 1920 as "Music of the Ainur", and then completely rewrote it in 1930. He continued to make further revisions throughout his life. The early version was eventually published by his son Christopher in The Book of Lost Tales 1.

J. R. R. Tolkien, a devout Roman Catholic, embodied Christianity in his legendarium, including The Lord of the Rings. Light is a prominent motif in Christianity: it is the first thing created by God in the Book of Genesis, it symbolizes God's grace and blessings elsewhere in the Old Testament, and it is closely associated with both Jesus and humanity itself in the Gospel of John in the New Testament.

In The Silmarillion, light is similarly important. It appears early on in the Years of the Lamps, with two enormous lamps atop mountain-sized pillars to light the world of Arda. When these are destroyed by the Dark Lord Melkor, they are replaced by the Two Trees of Valinor, which provide light for the new home of the Valar. When these too are destroyed, the Valar use their last fruit and their last flower to create the Sun and the Moon. A little of the light of the Two Trees is captured in the Silmarils, the crafted jewels that give the book its name. These are coveted by the Dark Lord, provoking war and the destruction of much of the world of Elves, Men, and Dwarves. A survivor, Eärendil, sails across the Great Sea to ask the Valar to intervene; they expel the Dark Lord, and Eärendil and his ship Vingilot sail the heavens as the Morning Star.