Oh, the depth of the love of Christ! :

First, we know the depth of someone’s love for us by what it costs him: if he sacrifices his life for us, it assures us of deeper love than if he only sacrifices a few bruises. So [we see] the depth of Christ’s love by the greatness of what it cost him.
Second, we know the depth of someone’s love for us by how little we deserve it. If we have treated him well all our life, and have done all that he expects of us, then when he loves us, it will not prove as much love as it would if he loved us when we had offended him, and shunned him, and disdained him. The more undeserving we are, the more amazing and deep is his love for us. So [we see] the depth of Christ’s love in relation to how undeserving are the objects of his love (Romans 5:5-8).
Third, we know the depth of someone’s love for us by the greatness of the benefits we receive in being loved. If we are helped to pass an exam, we will feel loved in one way. If we are helped to get a job, we will feel loved another way. If we are helped to escape from an oppressive captivity and given freedom for the rest of our life, we will feel loved another way. And if we are rescued from eternal torment and given a place in the presence of God with fullness of joy and pleasures forevermore, we will know a depth of love that surpasses all others (1 John 3:1-3). So [we see] the depth of Christ’s love by the greatness of the benefits we receive in being loved by him.
Fourth, we know the depth of someone’s love for us by the freedom with which they love us. If a person does good things for us because someone is making him, when he doesn’t really want to, then we don’t think the love is very deep. Love is deep in proportion to its liberty. So if an insurance company pays you $40,000 because you lose your spouse, you don’t usually marvel at how much this company loves you. There were legal constraints. But if your Sunday School class makes all your meals for a month after your spouse dies, and someone calls you every day, and visits you every week, then you call it love, because they don’t have to do this. It is free and willing. So [we see] the depth of Christ’s love for us in his freedom: “No one takes my life from me; I lay it down of my own accord” (John 10:18).
~John Piper

“How deep the fathers love for us
How vast beyond all measure
That He should give his only son
To make a wretch His treasure

How great the pain of searing loss
The Father turns His face away
As wounds which mar the Chosen One
Bring many sons to glory

Behold the Man upon the cross
My sin upon His shoulder
Ashamed I hear my mocking voice
Call out amoung the scoffers

It was my sin that held Him there
Until it was accomplished
His dying breath has brought me life
I know that it is finished

I will not boast in anything
No gifts no power no wisdom
But I will boast in Jesus Christ
His death and resurrection

Why should I gain from His reward
I cannot give an answer
But this I know with all my heart
His wounds have paid my ransom”