38. This saving faith which we profess is sustained by the spirit of prophecy, speaking with one voice through many mouths, and never, through long and changing ages, bearing an uncertain witness to the truths of revelation. For instance, the words which, as we are told through Moses, were spoken by God the Only-begotten, are confirmed for our better instruction by the prophetic spirit, speaking this time through those men of stature,—For God is in Thee, and there is no God beside Thee. Thou art God, and we knew it not, O God of Israel, the Saviour. Let heresy fling itself with its utmost effort of despair and rage against this declaration of a name and nature inseparably joined, and rend in twain, if its furious struggles can, a union perfect in title and in fact. God is in God and beside Him there is no God. Let heresy, if it can, divide the God within from the God within Whom He is, and classify, Each after His kind, the members of that mystic union. For when He says God is in Thee, He teaches that the true nature of God the Father is present in God the Son; for we must understand that it is the God Who is Exod. iii. 14.that is in Him. And when He adds, And there is no God beside Thee, He shews that outside Him there is no God, since God’s dwelling is within Himself. And the third assertion, Thou art God and we knew it not, sets forth for our instruction what must be the confession of the devout and believing soul. When it has learnt the mysteries of the Divine birth, and the name Emmanuel which the angel announced to Joseph, it must cry, Thou art God, and we knew it not, O God of Israel, the Saviour. It must recognise the subsistence of the Divine nature in Him, inasmuch as God is in God, and the nonexistence of any other God except the true. For, He being God and God being in Him, the delusion of another God, of what kind soever, must be surrendered. Such is the message of the prophet Isaiah; he bears witness to the indivisible and inseparable Godhead of Father and of Son.