No surprise there. If it supports you, okay. If not, then:

- it was written (insert date here that suits argument)

- yes, but it was contradicted by (name of book left out of the canon)

- when (name here) translated it, he (insert embellishment) the text

and so on.

It is possible, but not certain, that Paul did not himself write the epistle. It may have been written by a disciple of Paul. It is completely consistent with Paul’s thought, and was certainly written while one or more Apostles was still alive.

What it makes clear is Jesus’ identity with the Word that made the universe, also reflected in John’s Gospel.