Finding your path to Hashem

Rashi says Hashem answered Yitzchak's prayer and not Rivka's, because he was a tzaddik son of a tzaddik and she was a tzaddekes from a wicked home. That seems backwards, since rising above a bad home should count for more. The same question sits under the opening of Parshas Pinchas, which repeats that Pinchas was the grandson of Aharon, a man of peace, right after Pinchas did something that looked like the opposite of peace. What does it mean to find your own way to Hashem inside the home you grew up in? A grade eight math teacher, always calm, shows it.