What did Abraham’s father, an idol worshiper, do to deserve to have a son like Abraham?
Hi! I have been giving your question a lot of thought, and consulting with some of my own teachers. Still, the following is no more than my own opinion:
When we say that a father “deserves” a certain son, or (in Hebrew) that he is “zoche” to such a child, we mean that it is a benefit to the father. Since the child is in some ways an extension of the parent, physically and spiritually, so the greatness of the child benefits the father, who is connected. The more that the father was the source of the son’s greatness, of course, whether because of his teaching or his example, the more this will be true.
I feel that Abraham was an exception to this usual rule. There is no question that his father’s genes, his abilities, etc., appeared in the son. They were the primary direct line of Shem the son of Noah, as the Torah details. Still, the Torah stresses that Abraham’s whole task was to be completely disconnected from the world and the teachings his father represented. He is ordered to leave his father’s house, a command given to no other. The Maharal of Prague comments that he represented a new beginning, a way that he had to carve on his own. I don’t think his father could claim credit for any of this. Indeed, it says in Pirkei Avos (Chapters of the Fathers) that Abraham came along at the end of the ten generations and “received the reward of all of them”. That would include his father.
I want to stress that I don’t think this applies to most of those who return to Judaism in our days. Very frequently, they come to the Torah based on a bedrock of values and love for good which they gained from their parents.
Best wishes,
Michoel Reach