Isaiah 9:6 Proves the Trinity, not the "Oneness". Anti-trinitarian "Oneness" is heresy. Isaiah 9:6 is a prophecy of the incarnation of the Word, who takes on the attributes of the Godhead in His Person. Jesus contains all of the attributes of God in Himself, as the express image of God.
Jesus is the "everlasting father" in Creation, our father in the sense that we are begotten by the Word, but He is not "God the Father", but rather, the Son of God, the 2nd Person of the Holy and Blessed Trinity. He is co-equal with God the Father and the Holy Spirit, but willingly submits His will to God the Father, who is the 1st Person of the Holy Trinity.
This is an orthodox Christian teaching of the faith; let him who rejects it be anathema.
From the Sermon: "The Trinity vs. 'Oneness' Heresy", by Afshin Yaghtin: [ Ссылка ]
