God must be who he is

"For God to condone or ignore the dishonor heaped upon him by the sins of men would be tantamount to giving credence to the value judgment men have made in esteeming God more lowly then his creation. It is not so much that he would be saying sins do not matter or justice does not matter; more basically, he would be saying that he does not matter. But for God thus to deny the infinite value of his glory, to act persistently as if the disgrace of his holy name were a matter of indifference to him-this is the heart of unrighteousness. Thus if God is to be righteous he must repair the dishonor done to his name by the sins of those whom he blesses. He must magnify the divine glory man thought to deny him.

It is pointless here to object that God is never trapped in a situation where he must do something. This is pointless because the only necessity unworthy of God is a necessity imposed on him from causes not originating in himself. To say that God must be who he is, that he must value what is of infinite value and delight in his infinite beauty, this is no dishonor to God. On the contrary, what would dishonor God is to deny that he has any necessary identity at all and to assert that his acts emerge willy-nilly from no essential and constant nature." (Piper, John. The Justification of God. Grand Rapids: Baker Academic, 1993. 148)

God's righteousness, and man's

Therefore, these prophetic writings, along with many other texts, impress upon the careful reader of the Old Testament that all God's saving deeds spring ultimately form his loyalty to his own name. This impression then functions to confirm for the reader the insight derived elsewhere from numerous explicit connections that the righteousness of God consists most basically in God's unswerving commitment to preserve the honor of his name and display his glory. Thus if God ever abandoned this commitment and no longer sought in all things the magnifying of his own glory, then there indeed would be unrighteousness with God...To treat adequately the implications of this thesis for the righteousness of man in the Old Testament would require too much space here...The basic implication as I see it is that man's righteousness will be seen now as radically God-centered. The relational accent is in no way diminished, but it receives a distinct orientation: the righteousness of man in relation to God is (reflecting God's righteousness) to love the honor of God's name, to esteem above all things God's glory (especially as it has been mercifully experienced in his saving deeds), and, finally, to do only those things which accord with this love and esteem. (Piper, John. The Justification of God. Grand Rapids: Baker Academic, 1993. 119)