Spirit of Faith: Sacrifice and Service is a compilation of writings and prayers that focus on sacrifice and service—subjects that are given great importance in the Bahai writings. The passages compiled here implore all people to make sacrifices and expend their energies in service to mankind as a means to improve the world of humanity and bring about its oneness. The Spirit of Faith series continues to explore spiritual topics—such as the unity of humanity, the eternal covenant of God, the promise of world peace, and more—by presenting what the central figures of the Bahai Faith have written regarding these important topics.