Reviewer John Hesselink states that Hart's Calvinism: A History (2013) compares favorably with the 1954 classic The history and character of Calvinism (1954) by John T. McNeil:
Hart's book is excellent in many ways. It supersedes McNeil's book if for no other reason than it benefits from later studies on Calvin as well as Reformation scholarship of the last 60 years. Moreover it deals with the worldwide spread of the Reformed tradition in Asia and Africa, areas not covered by McNeil.[4]
In a Wall Street Journal review of Calvinism: A History, Barton Swaim describes him as, "a cantankerous conservative, a stalwart Presbyterian and a talented polemicist with a delightfully perverse sense of humor."[5]
Stephen J. Nichols states that, like many other theologians, Hart is of the opinion that "theology, like nature, abhors a vacuum," in that theologizing is influenced by culture.[6]
Hart follows in the tradition of J. Gresham Machen (to whom he dedicated his book Secular Faith) in espousing an approach to politics that engages at the level of the individual rather than that of the church. Hart makes the observation that efforts, "to use Christianity for public or political ends fundamentally distort the Christian religion."[7] In Secular Faith Hart argues for the church to follow its mission by standing apart as a witness, suggesting that the nature of Christianity is "otherworldly", and criticizing those who "have tried to use their faith for political engagement".[8]