The author wrote this book "considering the renewed interest taken at present in questions of Church government and establishment," noting that "there seemed to be some room for a detailed treatment of a career which covers so interesting a period as that embraced between 1690 and 1750."

Macmillan is an important historical link to those who still fight for Christ's Crown and Covenant. "For many years he fought the battle of the Covenants alone, and he fought it on lines of policy and wisdom." states Reid.

Furthermore, the author continues,

"I have tried to indicate his position among the 'Suffering Remnant' by calling him 'a Cameronian Apostle;' for, during the long period of 36 years, he was the sole ordained minister among the scattered congregations of the 'Society' people. The name seems not unfitting, and it receives a certain sanction from the authority of Dr. Cunningham, who styled him the 'high-priest' of the Societies...

Further, Macmillan's story is also the record of the development of a most interesting side of Scottish Church life. He may be said, indeed, to have made the history of what, at last, became the Reformed Presbyterian Church. This is so true, that that Church long bore the popular name of the 'Macmillanites.' And the name of Macmillan is bound up with more than one congregation still existing."

An important book for those who would trace the backsliding of modern Presbyterianism (the neopresbyterians) and also be encouraged by the remnant of those who remain faithful to the position of the original Covenanters (the paleopresbyterians).

This book's 348 pages include illustrations and a detailed appendix containing important church documents.