None of the gospels are attributed to Paul, and none of the books of the Old Testament were written by Paul, so why would Pauline authorship be crucial for Ephesians to be inspired?
because the Epistles are regarded as inspired, and equivalent to the word of G*d — as has been told to me by a church preacher — as a result of the alleged author’s (Paul’s) direct contact with G*d, allegedly appearing to him while he was riding a horse (or something like that).