None of us are called to sacrifice our children on Mount Moriah. But some of us are called to forgive horrendous evils done to our children. It is interesting that the two kinds of acts have important features in common. In both cases, the actions are difficult precisely because of the agent's virtue, and if they are not difficult, then that is evidence that the agent is morally corrupt. There is a significant way in which forgiving the evil done to one's child is a way of sacrificing the child—of letting go.
We do have the intuition that an obligatory or supererogatory action is the more valuable the more difficult it is. But a further thing seems to be true: the obligatory or supererogatory action is even more valuable when the difficulty derives (in the right way) from one's virtue. Thus, if Abraham had a friend who was asked to sacrifice her car, and it was just as difficult for her to sacrifice her car as for Abraham to sacrifice his son, nonetheless Abraham's sacrifice would be the more valuable one, though the sacrifice of his friend would have significant value, too. Likewise, it may be just as difficult for someone to forgive damage to her property as it is for another to forgive harm to her child, but the latter forgiveness has the greater value.
I think a partial theodicy focusing on exercises of virtue which are incredibly difficult precisely because of the agent's virtue has promise. It has been suggested that God could have, say, created a world of utterly non-violent inquirers where the main virtues are things like perseverance and intellectual integrity, which do not require horrendous evils. But I am not sure such a world would have much of the kind of exercises of virtue I am talking about. In fact, it is plausible that cases where virtuous action is made very difficult precisely by virtue are going to have to be cases where one is facing grave evil.
(I am also reminded of Aristotle's remark that the virtuous man fears death more, for the death of a virtuous man is a greater evil. This point might be relevant, also, to the death of Christ.)