From John Owen’s Christologia

No small part of the eternal blessedness of the holy God consisteth in the mutual love of the Father and the Son, by the Spirit. As he is the only-begotten of the Father, he is the first, necessary, adequate, complete object of the whole love of the Father. Hence he says of himself, that from eternity he was “by him, as one brought up with him: and was daily his delight, rejoicing always before him,” Proverbs 8:30 – which place was opened before. In him was the ineffable, eternal, unchangeable delight and complacency of the Father, as the full object of his love. The same is expressed in that description of him, John 1:18, “The only-begotten Son, who is in the bosom of the Father.” His being the only-begotten Son declares his eternal relation unto the person of the Father, of whom he was begotten in the entire communication of the whole divine nature. Hereon he is in the bosom of the Father – in the eternal embraces of his love, as his only-begotten Son. The Father loves, and cannot but love, his own nature and essential image in him.

Herein originally is God love: “For God is love,” 1 John 4:8. This is the fountain and prototype of all love, as being eternal and necessary. All other acts of love are in God but emanations from hence, and effects of it. As he does good because he is good, so he loveth because he is love. He is love eternally and necessarily in this love of the Son; and all other workings of love are but acts of his will, whereby somewhat of it is outwardly expressed. And all love in the creation was introduced from this fountain, to give a shadow and resemblance of it.

Love is that which contemplative men have always almost adored. Many things have they spoken to evince it to be the light, life, lustre and glory of the whole creation. But the original and pattern of it was always hid from the wisest philosophers of old. Something they reached after about God’s love unto himself, with rest and complacency in his own infinite excellencies; but of this ineffable mutual love of the Father and the Son, both in and by that Spirit which proceeds from them both, they had neither apprehension nor conjecture. Yet, as herein does the principal part (if we may so speak) of the blessedness of the holy God consist, so is it the only fountain and prototype of all that is truly called love; – a blessing and glory which the creation had never been made partaker of, but only to express, according to the capacity of their several natures, this infinite and eternal love of God! For God’s love of himself – which is natural and necessary unto the Divine Being – consists in the mutual complacency of the Father and the Son by the Spirit. And it was to express himself, that God made any thing without himself. He made the heavens and the earth to express his being, goodness, and power. He created man “in his own image,” to express his holiness and righteousness; and he implanted love in our natures to express this eternal mutual love of the holy persons of the Trinity. But we must leave it under the veil of infinite incomprehensibleness; though admiration and adoration of it be not without the highest spiritual satisfaction.

Again, he is the peculiar object of the love of the Father, of the love of God, as he is incarnate — as he has taken on him, and has now discharged, the work of mediation, or continues in the discharge of it; that is, the person of Christ, as God-man, is the peculiar object of the divine love of the Father. The person of Christ in his divine nature is the adequate object of that love of the Father which is “ad intra” — a natural necessary act of the divine essence in its distinct personal existence; and the person of Christ as incarnate, as clothed with human nature, is the first and full object of the love of the Father in those acts of it which are “ad extra”, or are towards anything without himself. So he declares himself in the prospect of his future incarnation and work, “Behold my servant, whom I uphold; mine elect, in whom my soul delighteth,” Isaiah 42:1. The delight of the soul of God, his rest and complacency — which are the great effects of love — are in the Lord Christ, as his elect and servant in the work of mediation. And the testimony hereof he renewed twice from heaven afterwards, Matthew 3:17, “Lo, a voice from heaven, saying, This is my beloved Son, in whom I am well pleased;” as it is again repeated, Matthew 17:5. All things are disposed to give a due sense unto us of this love of God unto him. The testimony concerning it is twice repeated in the same words from heaven. And the words of it are emphatical unto the utmost of our comprehension: “My Son, my servant, mine elect, my beloved Son, in whom I rest, in whom I delight, and am well pleased.” It is the will of God to leave upon our hearts a sense of this love unto Christ; for his voice came from heaven, not for his sake, who was always filled with a sense of this divine love, but for ours, that we might believe it. This he pleaded as the foundation of all the trust reposed in him, and all the power committed unto him. “The Father loveth the Son, and has given all things into his hand,” John 3:35. “The Father loveth the Son, and showeth him all things that himself does,” John 5:20. And the sense or due apprehension of it is the foundation of Christian religion. Hence he prays that we may know that God has loved him, John 17:23, 26. In this sense, the person of Christ is the “prooton dektikon” — the first recipient subject of all that divine love which extends itself unto the church. It is all, the whole of it, in the first place fixed upon him, and by and through him is communicated unto the church. Whatever it receives in grace and glory, it is but the streams of this fountain — love unto himself.

[HT: The Institute of Reformed Baptist Studies]