The similarities between the Middle Earth creation myth and the biblical creation story are significant because the reader is introduced to Tolkien's world on familiar ground.
Genesis begins with the famous line, "In the beginning God created the heavens and the earth." Similarly the "Valaquenta" in The Silmarillion begins, "In the beginning Eru [Iluvatar], the One made the Ainur of his thought; and they made a great Music before him. In this music the world was begun." The repetition of this famous biblical phrase suggests an immediate connection between Eru and God. Furthermore, Eru is referred to as "the One" just as the biblical phrase, "I am the Alpha and the Omega," sums up the Judeo-Christian understanding of the sole existence of God." This immediate allusion to the Judeo-Christian God is significant because it introduces the reader to the mythology of Middle Earth with a familiar and accessible figure. The allusion is also extended beyond just the creator. The description of the Valar seems to reference angels. They are defined as "Holy Ones" and the allusion is completed with the fall of Melkor for coveting power beyond his allotment. This extended connection to the biblical creation story provides the reader with an avenue in which to begin to conceptualize this new and strange world of Middle Earth. This is what Tolkien meant when he wrote in a letter to Milton Waldman, .
On the side of mere narrative device, this is, of course meant to provide beings of the same order of beauty, power, and majesty as the gods of higher mythology which can yet be accepted - well, shall we say baldly, by a mind that believes in the Blessed Trinity. .
In essence, the similarities to the Judeo-Christian creation myth are deliberate devices which depict Tolkien's understanding of his audience as well as lay the groundwork for a consistent thematic style throughout his mythology.
Another example of Tolkien's use of this type of connective device is evident through an association of Melkor to the Satan figure.