But God demonstrated his own love for us in this: while we were sinners, Christ died for us. -Rom 5.8
Four out of the last seven times I've prayed publicly (that is, with other people), I somehow found myself saying this or something similar to this line:
"...and we thank you that you love us because-"
And then I'll awkwardly stumble around with my words before getting back into stride. I can't believe I've never thought about this, but there's really no easy way to answer that question. asking "why does God love us?" gets at the heart of unconditional love. There's no reason or rhyme to it. It's absurd. The only explanation I can think of is Ephesians 1.11-12
"In him we were also chosen, having been predestined according to the plan of him who works out everything in conformity with the purpose of his will, in order that we, who were the first to hope in Christ, might be for the praise of his glory."
So ultimately God's love for us as shown in the cross is for the ultimate end of his glory. All the same, that doesn't really help me grasp the ludicrous extravagance of his mercy, that we who were once at war with God would be bought back into his camp at the price of his only-begotten son. This is a thought too wonderful for me, too lofty for me to attain. But it is in the heart of the gospel.
O Lord, I am astonished at the difference
between my receivings and my deservings,
between the state I am now in and my past gracelessness,
between the heaven I am bound for and the hell I merit.
Who made me to differ, but thee?
for I was no more ready to receive Christ than were others;
I could not have begun to love thee hadst thou not first loved me,
or been willing unless thou hadst first made me so.
O that such a crown should fit the head of such a sinner!
_ such high advancement be for an unfruitful person!
_ such joys for so vile a rebel!
Infinite wisdom cast the design of salvation into them mold of purchase and freedom;
Let wrath deserved be written on the door of hell
But the free gift of grace on the gate of heaven.
Let thy love draw me nearer to thyself,
wean me from sin, mortify me to this world, and make me ready for my departure hence.
-Adapted from Valley of Vision, by Arthur Bennett