A God Who Is Not Obligated

I'm reading through The Pleasures Of God by John Piper (I know, big surprise). The truths Piper exhorts from Scripture are so incredible...

"But the gospel is the good news that God is the all-satisfying end of all our longings, and that, even though he does not need us, and is in fact estranged from us becaouse of our God-belittling sins, he has, in the great love with which he loved us, made a way for sinners to drink at the river of his delights through Jesus Christ. And we will not be enthralled by this good news unless we feel that he was not obliged to do this." - Pg. 196