William Louis Roberts (1798-1864) was a Reformed Presbyterian minister, who studied under James Renwick Willson (1780-1853) at Coldenham, New York, and who is, like his mentor, regarded as one of the great ministers of the Reformed Presbyterian Church of North America in the 19th century.
In Roberts' The Reformed Presbyterian Catechism (1853), we have set before us the distinctive principles of the RPCNA, as officially held to at that time. In the introduction, he sets forth the focus of this ecclesiastical catechism:
"Question. How many are the peculiar and more prominent principles of the Reformed Presbyterian church?
Q. What are these?
A. The doctrines of
1. Christ’s Mediatorial Dominion in general.
2. his Exclusive Headship over the Church.
3. The supremacy and ultimate authority of the word God in the church.
4. Civil government a moral ordinance of God.
5. Christ’s headship over the nations.
6. The subjection of the nations to God and to Christ.
7. The word of God the supreme rule in the state.
8. The duty of nations to acknowledge and support the true Christian religion.
9. The spiritual independence of the Church of Christ.
10. The right and duty of dissent from an immoral constitution of civil government.
11. The duty of social covenanting, and the permanent obligation of religious covenants.
12. The application of these doctrines in the form of a practical testimony, to the civil governments where Reformed Presbyterians reside.
Q. What is meant by 'peculiar' principles?
A. Those which distinguish Reformed Presbyterians from other Christian denominations.
Q. What is meant by 'prominent' principles?
A. Those which, though held by some other denominations, are not made practically a part of their testimony."
All of these doctrines are expounded upon with Scripture references, and they demonstrate the Biblical grounds for the RPCNA's emphasis on, in particular: 1) Christ's mediatorial kingship over all nations; 2) political dissent from immoral civil government; and 3) the duty of social covenanting.
If you are interested to read an ecclesiastical catechism that teaches what American Reformed Presbyterians in 19th century believed in distinction to other groups of American Presbyterians, this is the book for you.