I am glad that I no longer live my life with that sort of mindset. Thinking that there is this omnipotent, omniscient God who loves us all and interacts with our world and chooses to intervene with some people and not with others. Just because he shows mercy to some does not mean he is merciful or deserves praise for it. We must also consider his withholding of mercy as well.
Consider: There is some horrible disease affecting the population. All who have it will suffer and die from it. I, however, have engineered a cure for it which only I possess. I have a near unlimited cache of it, more than enough to go around. Giving it to people simply requires them getting the pill.
Further, we might also consider, to make it a better analogy, that I was the one who first unleashed the horrible disease on the population. I did this because the population acted contrary to my desires. I had given the population many great advances, including medicinal, agricultural, and technological.
Are you, then, to call me merciful and benevolent if I arbitrarily only give it to some people and not to others? What of the people I don't give it to? Are you to simply say: "It was by his grace and wisdom that he has the cure which is so easily disseminated. He has no obligation to us, the man who had given us so much. If he chooses not to give the cure to some people, that is his will; his right to show or not show mercy, as it is 'unmerited.'"
What a terrible mindset one must be in to call someone merciful and benevolent who would withhold a cure for something which costs the person no money or time to disseminate. I am glad I am not of that mindset, personally.