Gillespie’s view of Christ’s kingship in relation to the nations is extensively set out in the pamphlets he wrote an answer to the publications of the Rev. Thomas Coleman, an Assembly commissioner and rector of St. Peter’s Church, Cornhill, in London. Coleman held Erastian views, believing that the church should be subject to the authority of the state—a view anathema to Scots Presbyterians. In three pamphlets… Gillespie set out a very different position.
At the heart of the debate is Coleman’s view that Christian magistrates are to manage their office “under Christ and for Christ,” a principle that might be expected to receive hearty assent from Gillespie. Coleman, however, bases his position on the view that all government has been given by Christ as Mediator, support for this claim being drawn from Ephesians 1:21–23. Gillespie responds that such a view robs pagan or infidel magistrates of their title to rule, since there is no way by which a pagan magistrate can derive authority from Christ as Mediator. This serves to expose the fundamental difference between Gillespie and Coleman. While both believe that Christ as Mediator is head of the church and that he is also supreme over the nations, they disagree as to whether the latter is as the eternal Son or as the incarnate Mediator. As Gillespie asserts, “God and nature hath made magistrates, and given them great authority; but from Christ as Mediator they have it not.”
— David Mackay, “From Popery to Principle: Covenanters and the Kingship of Christ,” 138–39 in Anthony T. Selvaggio ed. The Faith Once Delivered