It is hard to imagine a more disparate couple than Yitzchak and Rivka, the quiet contemplative husband who would "meditate in the fields" (24:63), and the worldly, independent-thinking wife who “ran again to the well” (Breisheet 20:24). Yitzchak spent his entire life in the land of Israel, never traveling the world. He was, as our Sages describe him, "a pure offering", ready to sacrifice himself to G-d. He could see no evil in others, and thus could be easily fooled by both Eisav and Yaakov.
There is no greater challenge than that of raising refined children. It is a task with so many variables and fraught with such difficulty that many a wonderful home produces children who do not follow in the paths of their parents.
It is quite evident that Yitzchak and Rivka had differences of opinion regarding the difficult task of raising their twin boys. Their contradictory assessments of Eisav and Yaakov continued to the end of their days. Rivka sensed that Eisav would not, could not, be rehabilitated from his nefarious ways, whereas Yitzchak never gave up hope that Eisav would ultimately remain a Jew.