in Malachi 2:10, it was written “'Is there not one Father of us all? Did not one God create us? Why, then, do we break faith with one another, profaning the covenant of our ancestors?”, yet in Isaiah 9:5, it was written: “For a son has been born for us, a son has been given to us, and dominion has been laid on his shoulders; and this is the name he has been given, ‘Wonder-Counsellor, Mighty-God, Eternal-Father, Prince-of-Peace’”, since there is only one Father, and that the Son is different than the Father, how would one explains this passage? My friend, a oneness Pentecostal is asking me and I need an answer
The Oneness Pentecostals argue that there is only one divine person, and that Christ is the Father. The argument here is that there is only one Father, and because this prophecy of Jesus gives him the name of “Eternal Father” he must actually be God the Father. Your friend claims that there cannot be two distinct persons bearing the heavenly name of Father.
But this passage from Isaiah 9:5 (and its comparison with Malachi 2:10) does not actually prove his point. Consider the below passage from a Jewish Bible commentary:
Isaiah 9:5
“The Mighty God…ruler”: This long sentence is the throne name of the royal child. Semitic names often consists of sentences that describe God; thus the name of Isaiah in Hebrew means “The LORD saves”; "Hezekiah, “The LORD strengthens”; in Akkadian, the name of the Babylonian king Merodach-baladan (Isa. 39:1) means “the god Marduk has provided an heir.” These names do not describe that person who holds them but the god whom the parents worship. Similarly, the name given to the child in this v. does not describe the child or attribute divinity to him, contrary to the classical Christian readings of this messianic verse.
-Adele Berlin and Marc Zvi Brettler, eds.,
The Jewish Study Bible (Oxford University Press, Inc.: New York, 2004), 802.
Obviously, as Christians we would disagree with that last line of the commentary. But the point is that, according to the nature of Semitic names, the Messiah has the title of “Eternal Father” and is
still considered a distinct person from God the Father. The Jews have read Isaiah and Malachi for several centuries, and they never believed that the passages in question indicated that the Messiah would actually be God the Father (as opposed to a person distinct from the Father).
From the aspect of Trinitarian theology, the verses in question simply illustrate the mystery of the Holy Trinity, that Jesus is distinct from the Father and, at the same time, is the Father.