As we investigate the work of Sir Isaac Newton, it becomes clear that for this genius, all of modern mathematics and physics are seen as an extension of a spiritual reality. Calculus is the mathematical plan by which the universe was designed, according to Newton; his astronomical observations and his refinements in telescope design were done largely with an eye to calculating the dates of events in the Bible through stellar movement. Yet, for this most religious of men (Newton wrote more books about God and the Bible than he wrote about mathematics and physics), the exact nature of his religious beliefs remains a matter of controversy.
Newton spent most of his life in or near the university in Cambridge, England.
Some historians are inclined to view Newton as a Christian, because Newton does clearly state that Jesus is both the Savior of all humans and the Son of God. Further, he clearly states that Jesus rose from the dead, in the most physical and bodily sense. Finally, Newton proclaimed that the texts of the Tanakh and the New Testament were historically true and literally accurate; Newton wrote entire books, commenting in detail about the writing of the prophets (he could read Hebrew and Greek very well). All of which would make it seem that Newton is probably a Christian.
Yet other historians say that Newton was not, technically speaking, a Christian. They imply that Newton developed some very radical religious views, so strange that he cannot be called a Christian. First, Newton doubted the usual sense of the Trinity: Newton claimed that, although Jesus is both the Son of God and the Savior of the human race, yet Jesus is not identical with God nor equal to God. Second, Newton engaged in some rather occult practices, including the practice of alchemy (in the broader sense of magical chemistry, rather than the narrower sense of the attempt to synthesize gold). These two factors may be enough to make it questionable whether or not Newton can accurately be called a Christian.
Newton's chief work was published in 1687 under the title Philosophiae Naturalis Principia Mathematica, meaning Mathematical Principles of Natural Philosophy. In one of his history books, written around the same time but published later, he wrote, “I take it for granted that the Passion was on Friday the fourteenth day of the month of Nisan, the great feast of the Passover on Saturday the fifteenth day of Nisan, and the Resurrection on the day following.”