The following was written by Rabbi Shmuley Boteach.
The most confusing story of the Bible involves G-d’s commandment to Abraham to sacrifice his son Isaac. What was this G-d, who would later declare that all human, and especially child, sacrifice to be an abomination, thinking?
The most insightful commentary I have seen on this story comes from the Lubavitcher Rebbe, Rabbi Menachem Schneerson, who says that the key to the story is to see Isaac not as an individual but as a religion. Who was Isaac? He was Judaism. He was the person who would continue Abraham’s belief system. With his death, everything that Abraham had taught in terms of his rejection of paganism and the belief in one G-d would be lost.
The test, therefore, was this: Would Abraham follow G-d’s commandment to kill off his religion or would he put his religion before G-d’s will? What really mattered to Abraham? G-d or Judaism? And if they were to be put in conflict, what would he choose? The religious fanatic is the man or woman who has ceased to serve G-d and has begun worshipping their religion, making their faith into yet another false idol. Religion is solely the means by which by which we come to have a relationship with our Creator. But when it becomes a substitute for G-d it becomes soulless and fanatical, seeing as there is no loving deity to temper it.