 Christianity and other monotheistic religions (Islam and Judaism) assume a transcendent and sovereign God who created the universe and continually maintains its existence. The world only exists because of an ultimate and supernatural cause which is, as Newton said, “not blind and fortuitous, but very well skilled in Mechanicks and Geometry” (Cohen 1978, 282). Whether in a general philosophical sense or in a scientific sense, cosmology has always been part of theism, but it is only relatively recently that cosmology based on physics and astronomy has entered the discussion concerning the existence and role of God. A limited application of physics to the study of the universe can be found in the second half of the nineteenth century when the cosmological consequences of the law of entropy increase were eagerly discussed in relation to the Christian doctrines of a world with a beginning and end in time. However, physical cosmology is essentially a twentieth century science which emerged as a result of the discovery about 1930 that the universe is in a state of expansion that possibly started a finite time ago. Cosmology as a subdiscipline of physics differs in some respects from mathematical, philosophical and classical observational cosmology, but of course the different approaches are in constant interaction. In a modern sense, physical cosmology became established after the discovery of the cosmic microwave background in 1965 which quickly turned the hot big bang model into the standard model of the universe. Jim Peebles’ Physical Cosmology of 1971, possibly the first book with this title, may be taken as the beginning of modern physical cosmology.