Like a father is merciful to his children, so the Lord is merciful to those who fear him. (Psalm 103:13)
And I will spare them, as a man spares his own son who serves him. (Malachi 3:17)
These passages from the Old Testament speak of God as merciful and compassionate. Those who receive instruction from the New Testament learn that "God is love", and that "God so loved the world" (etc). We find nothing unusual in thinking of God as loving. But for some philosophers, the idea of God having emotions causes a problem within their philosophical systems. As the medieval Jewish thinker Maimonides commented on the two passages above:
Such instances do not imply that God is influenced by a feeling of mercy, but that acts similar to those which a father performs for his son, out of pity, mercy, and real affection, emanate from God solely for the benefit of his pious men, and are by no means the result of any impression or change [produced in God].
[and again] ... not the result of any emotion, for He is above all defect!
(Guide for the Perplexed: Part I, Chapter LIV)
He felt the need to claim that the human father acts out of "real affection" but that God acted in a similar way "solely for the benefit of his pious men." Emotion was considered to be a defect, at least in the sense of an outside influence. God was considered to be absolutely unchanging and immovable. His essence was considered to be simple, in the sense that nothing was added to it. If God felt emotion, then something outside of God had influenced God, or there was something besides God's essence at work in God. Maimonides reasoned that emotions were attributed to God as a figure of speech, to communicate that God did things that, in a human, we would attribute to a certain emotion. How could Maimonides attribute emotions to God when he considered emotions to be a defect?
Before we return to the subject of whether emotions are a defect, we will look at one of the human examples that Maimonides gives for a time when someone -- here a human ruler -- should act without reference to his personal feelings:
Acts [of punishment] must be performed by him moderately and in accordance with justice, not merely as an outlet of his passion. He must not allow his passions to overcome him, for all passions are bad, and they must be guarded against as far as it lies in man's power. At times and towards some persons he must be gracious, not only from motives of mercy and compassion, but according to their merits. (continuing in chapter LIV)
Here it seems that the author distrusts our emotions because they are out of step with justice and the merits of the situation. The punishment might be out of proportion to the crime: the ruler may have an existing passion that needs an "outlet" -- the emotions are about something else besides the case before him. But would the appropriate emotions be wrong? Here the ruler has inappropriate ones. Or in the case of the ruler who needs to act graciously: he might not have the appropriate mercy and compassion when needed, and must act graciously despite the lack of genuine feeling. But in that case it is not the mercy or the compassion that is a defect; it is the lack of them that is a defect. So I find myself unconvinced by the argument that feeling itself is a defect.
Some would say that the change itself, when applied to God, is a defect: for God is said not to change. But suppose that a criminal lived his life in a destructive way causing harm to those he met, and God's will was against him. Now suppose the criminal had a change of heart, and began to repair the harm that he had done. He would then find that God's will was for him. But it was not God's will that changed. Even though the man found himself first as an object of God's displeasure and later found himself in God's favor, it is not God who changed. God was steadfast: against evil and for good. It was the man himself who changed sides.So I find myself unconvinced by the argument that God having genuine emotion means a "change" in God. His disposition could be steadfast.
Does God feel genuine mercy? And if so, does God change?
As the saying so often repeated within the Bible says:
His mercy endures forever. (references: too many to fit on a line)
If God does not change, then His mercy for the world is as unchanging as He is.