The fathers delight in the son and our response to it amplified by the thoughts of Richard Sibbes.

God loves himself and pursues his own glory because he views himself as the thing of greatest worth therefore God loves Jesus as he is the image of the father.

First as he is God, the Son of God, the engraven image of his Father, so he is primum amabile, the first lovely thing that ever was. When the Father loves him, he loves himself in him, so he loves him as God, as the second person, as his own image and character.

God delighted in the humanity of Jesus as Jesus was the greatest of all men and when god made man in the garden of Eden he was well pleased. So even more so he should be pleased with the greatest of all men his own workmanship.

And as man he loves him, for as man he was the most excellent creature in the world, he was conceived, fashioned, and framed in his mother's womb by the Holy Ghost. It is said, Heb. 10:5, God gave him a body. God the Father by the Holy Ghost fashioned and framed and fitted him with a body, therefore God must needs love his own workmanship.

There is nothing to displease the father in the son as the son had no sin in him and was perfect and so could not displease the father. Meaning God could not, not find delight in his son.

Again, there was nothing in him displeasing to God, there was no sin found in his life any way, therefore as man he was well pleasing to God. He took the manhood and ingrafted it into the second person, and enriched it there; therefore he must needs love the manhood of Christ, being taken into so near a union with the Godhead

God does whatever he pleases and therefore Jesus’ work as mediator would have been very pleasing to the father because it was ordained and decreed by him therefore was be his pleasure. So Jesus the one who performs the will of the father must therefore be the fathers pleasure.
As God and man mediator especially, he loves and delights in him. In regard of his office, he must needs delight in his own ordinance and decree. Now lie decreed and sealed him to that office, therefore he loves and delights in him as a mediator of his own appointing and ordaining, to be our king, and priest, and prophet.

The fathers delight is in the sons obedience unto death as well as the sons humiliation and incarnation to do the fathers will. For he we see the sons measure of love for the father as well as free voluntary submission to his will.

Again, he loved and delighted in him, in regard of the execution of his office both in doing and suffering. In doing, the evangelist says, 'He did all things well,' Mark 7:37. When he healed the sick, and raised the dead, and cured all diseases, whatsoever he did was well done. And for his suffering, God delighted in him for that, as it is in John 10:17, 'My Father loves me, because I lay down my life;' and so in Isa. 53:12, 'He shall divide him a portion with the great, because he poured out his soul unto death;' and in Phil. 2:9, 'Because he abased himself to the death of the cross, God gave him a name above all names:' therefore God loves and delights in him for his suffering and abasement.

God delight in Jesus is therefore caused by many a reason and drawn out by numerous motives.
Therefore God delighted in him, as God, as man, as mediator God-man, in his doings, in his sufferings, every way.

So lets conclude if the father who is omniscient knowing everything fully chooses to delight in the son then he must be a source of true delight. For the father would know if the son was not worth delighting in or if their was an object to which the delight was worth giving more too. Therefore how much more then should we delight in the Son if the father finds him to be so delightful. Our delight should be and can be found in Jesus Christ.