In this paper I follow Fabro’s analysis of “Dell’ente, dell’essere e del nulla” from the eighth chapter of his book Tomismo e Pensiero Moderno, and his explanation of essere and nulla in Heidegger and Aquinas. Remaining faithful to the author’s outline in said chapter, firstly, I highlight the essential topic of being and the openness to the Absolute in both, the Heideggerian and Thomistic metaphysical thought. Secondly, I consider the reduction of the object of metaphysics to the essence and the problem of being in Christian philosophy. Finally, I address Heidegger’s charge directed to Thomistic philosophy as interpreter of the faith. In the conclusion, by following some of the remarks of Fides et Ratio, I restate the importance of returning to Aquinas’ innovative notion of being, equally to do philosophy and theology in total openness to the Absolute, and I do so in the steps of Fabro, that is, recognizing the contributions of modern philosophy such as Heidegger’s.