John 10:29

These strong assertions He bases, as always, on the Father's will and power. ὁ πατήρ μου … ἐσμεν. “My Father who has given me these sheep is greater than all: and therefore no one can snatch them out of my Father's hand. But this is equivalent to my saying no one can snatch them out of my hand, for I and the Father are one.” ἐγὼ καὶ ὁ Πατὴρ ἕν ἐσμεν. Cf. John 17:21-23, ἵνα πάντες ἓν ὦσι. Bengel says: “ Unum, non solum voluntatis consensu, sed unitate potentiae, adeoque naturae. Nam omnipotentia est attributum naturale; et serino est de unitate Patris et Filii. In his verbis Jesu plus viderunt caeci Judaei, quam hodie vident Antitrinitarii.” But Calvin is right when he denies that the words carry this sense: “Abusi sunt hoc loco veteres ut probarent Christum esse Patri ὁμοούσιον. Neque enim Christus de unitate substantiae disputat, sed de consensu quem cum Patre habet: quicquid scilicet geritur a Christo Patris virtute confirmatum iri.” An ambassador whose demands were contested might quite naturally say: “I and my sovereign are one”; not meaning thereby to claim royal dignity, but only to assert that what he did his sovereign did, that his signature carried his sovereign's guarantee, and that his pledges would be fulfilled by all the resources of his sovereign. So here, as God's representative, Jesus introduces the Father's power as the final guarantee, and claims that in this respect He and the Father are one. Whether this does not involve metaphysical unity is another question. Cf. Tertullian, adv. Praxeam, 22; Hippolytus, c. Noetum, 7, δύο πρόσωπα ἔδειξεν, δύναμιν δὲ μίαν.