I don’t doubt that challenges are important and maybe even necessary in our lives, and true also that challenges involve frustration and suffering, in some cases. And I suppose you can say that meeting challenges helps to build character. (They surely are conditions for some of our greatest art!) But tell me, what character is built for the millions whose lives were cut short by the holocaust, by total war, by early deaths due to preventable disease? Is this the only way your God can “build character”?