The Chosen (Reuven Malter, #1)

It is the now-classic story of two fathers and two sons and the pressures on all of them to pursue the religion they share in the way that is best suited to each. And as the boys grow into young men, they discover in the other a lost spiritual brother, and a link to an unexplored world that neither had ever considered before. In effect, they exchange places, and find the peace that neither will ever retreat from again.