Tolkien’s impetus for writing was his belief that unlike the Romans, Greeks etc, the Ango-Saxons lacked a mythology. He thus set out to create his own
Anglo-Saxon I should say
In fact. The English had folklore, however. Tolkien sought to combine it with a sort of Norse-flavored mythology. Not a bad idea, by the look of it.
What I have read is that he, a philologist (and inspiration for CSL’s character, Elwin Ransom), created his own languages, and wanted to give them a home.
He further states in Tree and Leaf that he wanted to tell a story with a “eucatastrophe” (his coined word for a happy ending, like The Gospel).
Regardless, Asgard, Odin, Tyr, Thor, et cetera, certainly combine to form a mythology. Some days are named after them!