"Morality is partly a system of norms and reasons that human beings have developed in order to work and to live together. One of its functions is to regulate cooperation, conflicts of interest, and the division of labor and to specify the conditions under which some people have authority over others with respect to cooperative activities." (David B. Wong, Natural Moralities, p. 37)
It struck me as I read this sentence that some Christian philosophers might take issue with the anthropocentric notion that morality is something developed by human beings. They might rather say that morality is developed by God, for human beings. Or, would Christian philosophers have to disagree still further and deny that morality is for human society?
So, I ponder this:
If morality is for human society -- specifically, to enable cooperation bewteen individuals and groups by regulating conflicts of interest, etc. -- can God be moral?
And, does it make sense to talk about the moral goodness of God apart from consideration of God's relationships with human beings (or other created beings)?
To say God is (morally) good is to say, in part, that God's actions are limited. If there are no limits to divine activity (for example, if we cannot say that God would not torture an innocent person for no purpose but God's own pleasure), then God is not a morally good being. (It may well be the case that a good God does just whatever God wants to do, if all that God wants to do is good. So, it it need not be the case that there are limits external to God's desires or will or character-dispositions that place restrictions on how God acts).
I have difficulty imagining what a non-contigent Being, in a world that contains no other beings with which this Being might relate, might do that could be morally wrong. Such a solitary Being could not even have moral vices such as greed (there is nothing to covet) or selfishness or pride.
I am less certain in my intuitions on this point, but it also seems difficult to imagine what such a solitary Being might do that is morally good.
However, in Christian theology, we may draw upon the concept of the Social Trinity. Christian tradition does, indeed, use the concept of the Social Trinity to justify the theological claim that God is Love, in essence, and that God does not need to create any other beings in order to be a loving Being. InterPersonal relationships are part of the essence of the divine Being, and so God can be morally good in terms of these relationships. (The Father loves the Son, the Son loves and obeys and honors the Father, etc.)
In the Biblical narrative, the morality God gives to human society (specifically, the human society of the descendents of Israel gathered at Sinai) is a morality for human beings with the function of regulating their social relationships. The Christian philosopher might say that a good and true morality is one that reflects, or is analogous in the right way to, the social-ethical relationships within the economy of the Trinity. How does the moral goodness of God figure into the morality of ancient Israelite society? God does not stand apart from this society, but is one member of it (albiet a unique and important member--the one who calls the society into being in the first place: "The LORD your God who brought you out of the land of Egypt"). The moral goodness of God, in this social context, has to do with God's fulfilling God's covenantal obligations to Israel. Throughout the pages of the Hebrew scriptures, human beings (Abraham, Moses, Job, and the psalmists, for example) call upon God to maintain His reputation, to act according to His good moral character (that is, for the sake of His Name). These human beings appeal not only to God's covenantal promises, but also to the inherent mercy, grace, and lovingkindness in God's character. So, the moral goodness of God does involve more than what is specified in the social contract of Sinai (or with Abraham or Noah). But these other character attributes of God which constitute God's moral goodness: mercy, lovingkindness, justice are also character attributes that have to do with the way God relates to God's People, or to the nations.
So, when we say God is (morally) good, we are (typically) describing the way God relates (socially) to human beings. We are describing limits to how God might and does act, in relation to creatures. An account of morality, therefore, that characterizes morality in terms of its functions to promote social cooperation and harmony in relationships between individuals and between groups, can sensibly be applied to statements about the goodness of God.