Brooks' work depicts individuals of different religious faiths understanding the clear implications of protecting the Haggadah. There is something larger than individualistic differences that they recognize in their collaboration. At the same time, there is something powerful in their work together as they seek to avert an oppressive, external force.
In 1940s Sarajevo, the Nazi threat was an oppressive reality that sought to burn all books that were disapproved is what motivates someone of the Islamic faith to help preserve the Haggadah. Serif Kamal recognizes the existential threat posed. He wishes to save the Haggadah and in taking it to the mountains, he collaborates with the Jewish faith to preserve something that is larger than his own faith.
The Inquisition demonstrates another instance in which different religious backgrounds are transcended for something larger. Father Giovanni betrays his own Catholic position in signing the book so that it won't be burned by his own forces of persecution. Father Giovanni acknowledges that he, himself, is Jewish. Yet, the position in which he holds in society is Catholic. In this, he discards his own position of power to stand up for that which is opposite. Different religious backgrounds are put aside in the name of something larger.
Isabella's work with Dr. Netanel ha-Levi's family represents people from different religious backgrounds collaborating in the completion of the Haggadah. Isabella ends up painting the illustrations that go into the book. She does this for Dr. Netanel ha-Levi's son. In this, a Muslim artist helps to illuminate awork of the Judaic faith. The need to collaborate across religious elements on the completion of the Haggadah is evident at different points in the novel's narrative and the book's completion.