What is the theme in Palace Walk by Naguib Mahfouz?

Religion is a major theme in the story. Much of Palace Walk deals with characters, father and son, who are addicted to pleasures forbidden by Islam, alcohol consumption and adultery. Prosperous, prominent Ahmad Abd al-Jawad goes on nightly binges with his friends, puts of repentance until the end of his life in order not to have to forgo his pleasures, and sees no hypocrisy in his behavior. His cloistered wife, Amina, suspects what he is up to, but waits dutifully for him to come home so she can help him change clothes for bed.