But the same love is in the Father, for it is written: “God so loved the world, that He gave His Only-begotten Son” ( John 3:16).
So, then, the Father gave the Son, and the Son gave Himself.
Love is preserved and due affection is not wronged, for affection is not wronged where there is no distress in the giving up.
He gave one Who was willing, He gave One Who offered Himself, the Father did not give the Son to punishment but to grace.
If you enquire into the merit of the deed, enquire into the description of the affection.
The vessel of election shows plainly the unity of this divine love, because both the Father gave the Son and the Son gave Himself.
The Father gave, Who “spared not His own Son, but gave Him up for us all” (Rom. 8:32).
And of the Son he [St Paul] also says: “Who gave Himself for me” (Gal. 2:20).
“Gave Himself,” he says. If it be of grace, what do I find fault with. If it be that He suffered wrong, I owe the more.
But learn that in like manner as the Father gave the Son, and the Son gave Himself, so, too, the Holy Spirit gave Him. For it is written: “Then was Jesus led by the Spirit into the wilderness to be tempted by the devil” (Matt. 4:1).
So, too, the loving Spirit gave the Son of God.
For as the love of the Father and the Son is one, so, too, we have shown that this love of God is shed abroad by the Holy Spirit, and is the fruit of the Holy Spirit, because “the fruit of the Spirit is love, joy, peace, patience” (Gal. 5:22).
And that there is communion between the Father and the Son is plain, for it is written: “And our communion is with the Father and with His Son Jesus Christ” (1 John 1:3).
And in another place: “The communion of the Holy Spirit be with you all” (2 Cor. 13:14).
If, then, the peace of the Father, the Son, and the Holy Spirit is one, the grace one, the love one, and the communion one, the working is certainly one, and where the working is one, certainly the power cannot be divided nor the substance separated.
For, if so, how could the grace of the same working agree?
Ambrose of Milan (c. 337-397): On the Holy Spirit, Book 1, 12, 128-131.