In this treatise, the author offers a coherent structure of doctrine as he discusses the fundamental principles and leading applications of the doctrine of the church, primarily those commonly received among Scottish Presbyterians. Bannerman brings to the foreground such important topics as the Church's authority—how it received it and how it wields it—the Church's function, essential nature and peculiar characteristics, and the Scriptural form of church government and its relationship to the State.
Volume One of this two volume work (full title: The Church of Christ: a treatise on the nature, powers, ordinances, discipline, and government of the Christian Church) deals with the nature and power of the Church, containing a lengthy explanation of the Church in its relation to the state, which is arguably one of the best treatments of this topic available. From there it deals with matters in regard to which Church power is exercised (i.e. in regard to doctrine, ordinances, the instrumentality and time of public worship — with a discussion of holy days, Independency, and confessions). Volume Two continues where Volume One left off, providing a lengthy section on the sacraments, covering the parties in whom the right to exercise church power is vested, examining crucial points concerning Christian liberty, comparing the Popish, Prelatic, Independent, Congregational and Presbyterian systems, etc. Nine appendices deal with a wide range of practical topics including union between churches, Church/State relations, ordination, and valuable notes on the literature related to this subject.
Iain Murray, a prominent scholar and co-founder of the Reformed publishing house, The Banner of Truth Trust, has said of The Church of Christ that "for those who wish to study the doctrine of the Church in its several aspects as it was held by the majority of the Reformers, Puritans, Covenanters and leaders of 'The Third Reformation,' it will prove an invaluable textbook."