海德格哲學的根本問題——何謂「存有」？——經過其「基本存有論」之分析、透過對於「此在」之事實性的理解與詮釋，到底甚麼是「存有本身」（而非諸多「存在物」的存有），仍然難以獲得海德格肯定直接的說明。然而正因為海德格的思想瀰漫宗教的氛圍，即使被歸類為「世俗的」哲學，仍然對當代包括基督教與天主教在內的神學思想有巨大深遠的影響。雖然其上帝觀不同於或不能以傳統宗教的方式理解或涵蓋，但這正是海德格哲學可能帶給我們對於傳統宗教哲學與宗教現象的反省與檢視。本研究企圖探究海德格充滿神祕色彩的「存有」之問，以便嘗試發掘其哲學可能的宗教向度與意涵。本文主張其「存有」最終仍然必須以傳統宗教指稱的「上帝」觀之，然而，等同於「存有」的「上帝」是否還是ㄧ般宗教所理解的「上帝」，則是本研究嘗試釐清與論述的議題。

The essential question of Heidegger's philosophy: What is Being? —after his analysis of fundamental ontology and understanding and interpreting of Dasein's facticity—, it is hard to be clearly elucidated by Heidegger, what the ＂Being itself＂ (instead of Being of many beings) really is. However, because of the religious atmosphere pervading in Heidegger's thought, even if it might be categorized into the ＂secular＂ philosophy, it still exerts a great and profound influence upon the contemporary theological thoughts including Evangelical and Catholic ones. Although Heidegger's view of God is different from and cannot be comprehended or implied by the traditional religions, it is just that what his philosophy could offer us to reflect and examine in traditional philosophy of religion and religious phenomena. This study tries to explore the mystical question of ＂Being＂ by Heidegger, in order to discover the possible religious aspects and implications of his philosophy. This paper contends that Heidegger's ＂Being＂ must ultimately be regarded as a corresponding ＂God＂ of traditional religion; yet whether the ＂God＂ identified with ＂Being＂ is still a ＂God＂ in the sense of normal religions, is the issue this study attempts to clarify and expound.