Is God a superfluous hypothesis for modern cosmology? According to the normal understanding of modern science, the answer should be affirmative because modern science is supposed to be free of metaphysical and theological presuppositions. However, despite its self-proclaimed neutrality regarding metaphysics and theology, modern science is full of metaphysical and theological presuppositions. These can be summarized as a mechanistic understanding of nature, a reduction of God to an external agent in competition with natural processes, and creation to a worldly mechanism. These presuppositions are deficient and untenable, and they remain unconscious for the most part in the dialogue between science and theology, making it intellectually impossible because of the reduced notions of God, nature, and creation assumed. Using the coherent and unreduced image of God and nature provided by the Christian doctrine of creation ex nihilo, Fr. David Alcalde intends to uncover and criticize the incoherent theological assumptions inherent in a concrete branch of modern science, which is modern cosmology. The author points out the presence of these inadequate theological presuppositions in both the theologians who use modern cosmology to offer scientific proof for the existence of God and the atheistic cosmologists who use their science to reject the idea of God.