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 Bah?'? 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 Bah?'? Faith have written regarding these important topics.