B. B. Warfield on the Prodigal Son...

"In other words, its lesson is not that God loves His children, but that God loves sinners. And thus this parable is seen ranging with the preceding ones. The lost sheep, the lost coin, the lost son, have only this one thing in common, that they are lost; and the three parables unite in commending the one common lesson to us, that as men rejoice in the recovery of what is lost, so God rejoices in the recovery of sinners since sinners are the things that to Him are lost... What it teaches is that God will receive the returning sinner with the same joy that the father in the parable received the returning prodigal; because as this son was to that father's heart above all other things that he had lost, his lost one, and his return was therefore above all other things that might have been returned to him his recovery; so sinners are above all else that God has lost in the world His lost ones, and their return to Him above all other restorations that may be made to Him His recovery. The vivid picture of the father not staying to receive the returning son, but, moved with compassion as he spied him yet a great way off, running out to meet him and falling on his neck and kissing him in his ecstasy again and again; cutting short his words of confession with the command that the best robe be brought to clothe him, and shoes for his blistered feet, and a ring for his finger, and the order that the fatted calf be killed and the feast be spread, and the music and the dance be prepared because, as he says, "This my son was dead and is alive, was lost and is found " —  all this in the picture is meant to quicken our hearts to some apprehension of the joy that fills God's heart at the return of sinners to Him. 

"O brethren, our minds are dulled with much repetition, and refuse to take the impression our Lord would make on them. But even we - can we fail to be moved with wonder today at this great message, that God in heaven rejoices — exults in joy like this human father receiving back his son when sinners repent and turn to Him? On less assurance than that of Jesus Christ Himself the thing were perhaps incredible. But on that assurance shall we not take its comfort to our hearts? We are sinners. And our only hope is in one who loves sinners; and has come into the world to die for sinners. Marvel, marvel beyond our conception; but, blessed be God, as true as marvellous. And when we know Him better, perhaps it may more and more cease to be a marvel. At least, one of those who have known Him best and served Him most richly in our generation, has taught us to sing thus of His wondrous death for us:"

That He should leave His place on high,
And come for sinful man to die,
You count it strange ?—so do not I,
Since I have known my Saviour. 

Nay, had there been in all this wide
Wide world no other soul beside
But only mine, then He had died
That He might be its Saviour; 

Then had He left His Father's throne,
The joy untold, the love unknown,
And for that soul had given His own,
That He might be its Saviour!

"Is that too high a flight for us-that passion of appropriation by which the love of Jesus for me - my own personal soul - is appreciated so fully that it seems natural to us that He, moved by that great love that was in Him for me — even me — should leave His throne that He might die for me, — just me, — even were there none else beside? At least we may assent to the dispassionate recognition that in the depths of our parable is hidden the revelation of that fundamental characteristic of Jesus Christ by virtue of which He did become the Saviour at least of sinners. And seeing this and knowing ourselves to be sinners, we may acknowledge Him afresh today as our Saviour, and at least gratefully join in our passionate sinner's prayer:"

And oh! that He fulfilled may see
The travail of His soul in me,
And with His work contented be,
As I am with my Saviour! 

Yea, living, dying, let me bring
My strength, my solace from this spring,
That He who lives to be my King,
Once died to be my Saviour!

The Prodigal Son by B. B. Warfield, preached in the Chapel of Princeton Seminary on the text of Luke 15: 11-32, somewhere between 1910-1913.