Tolkien famously hated allegory, you are thinking of CS Lewis

It’s impossible to deny that Tolkien’s religious beliefs seeped pretty strongly into his books, and the reading of Gandalf as similar to Jesus is not at all an uncommon one.

However, as Tolkien famously said, it would be taking too strong a position to say that Gandalf is a “stand-in” for Jesus. Not allegory, but applicability.