Chaim Potok - Chosen (Penguin Books)

Following a baseball game that nearly became a religious war, two Jewish boys become friends. Danny comes from the strict Hasidic sect that keeps him bound in centuries of orthodoxy. Reuven is brought up żeby a father patently aware of the twentieth century. Everything tries to destroy their friendship, but they use honesty with each other as a shield and it proves an impenetrable protection.