[In rejecting Kevin Giles' accusation of ESS as subordinationism] Giles is right that all three persons are engaged in all of God's works and ways. However, only the Son—not the Father, nor the Holy Spirit— entered into hypostatic union with our humanity, and he did so forever. ...
His [the Son's -DHC] sending preceded his incarnation, and so his incarnate life and ministry can (as appropriate) reveal something of his eternal relations. If this were not so, we would be left with agnosticism, in flat contradiction to Jesus' own words that he who has seen him (in his lowliness) has seen the Father (John 14:9 et al.). ... [Robert Letham, The Holy Trinity: In Scripture, History, Theology, and Worship, (Phillipsburg, NJ: P&R, 2004), 494]
Giles even cites one of his heroes, Athanasius, to the effect that the divine Son willingly subordinated himself in the Incarnation (p. 37). But, we may ask, if he did so in the Incarnation without jeopardy to his deity, why is this not so in eternity? Since he has permanently united to himself the assumed human nature, does it not follow as something appropriate for the Son in his exaltation as well as in his humiliation, not as a slave to a master, but in the loving and willing communion of coequals? [Ibid., 495]
Quick, someone tell the "confessionalist" "pro-Nicene" crowd to take out their torches and pitchforks and start an inquisition of the "proto-Arian subordinationist heretic" Robert Letham...