It focused on the early and modern atheism, and the evidence of the existence of God in the Books of Al-Dhiya' and Burhaan Al-Haq and the interaction of Muslim youth with them, and the most important issues related to the subject. The thesis included an introduction, an overview, three chapters and a conclusion. The introduction comprised a presentation of the research plan, and the overview focused on the historical development of the issue, and the presentation of the two books, Al-Dhiya 'and Burhan al-Haqq and their authors. The first chapter comprised three sections, and dealt with the study of those who deny the existence of God, glory be to Him, in the past and present, and the approaches of early and contemporary Muslim scholars in proving the existence of God. As for the second chapter, it examined the evidence of the early scholars in proving the existence of God in the Dhiya, and the evidence of the contemporary scholars to prove the existence of God in Burhaan Al Haq. The last chapter analyzed the duty of the contemporary Muslims in proving the existence of God. In dealing with the issue of the existence of God, the study relied on the analytical and comparative methodology of the Al-Dhiya' and Burhaan Al-Haq. The study reached a number of results that show the diversity of atheist's proofs, past and present, and the development of the evidence for the existence of God Almighty. It also showed the necessity of paying attention to the contemporary Muslim youths and immunizing them from atheism by highlighting the role of science and reason in proving the existence of God, glory be to Him.