This item lays out the case for unity among churches, proving its assertions from:

• Thoughout Scripture
• Our Lord's declaring His will both in precept and prayer
• From apostolic practise
• From the covenanted Reformation's "Solemn League and Covenant" which lead to the production of the Westminster standards

Houston notes that in the Apostolic church "the government of the church was one and common wherever churches were planted. It was Presbyterian, and neither Prelatic, a system of monarchial despotism, nor Congregational, a system of popular democracy."
This biblical and Presbyterian uniformity was considered the apostolic, visible and doctrinal manifestation of the scriptural injunction to "one Lord, one faith, (and) one baptism."

Houston also points out that, "the only true and safe way of union is based on the platform of Scriptural uniformity; while that which is framed on allowing diversity in doctrine, and differences in government and worship, is a mere human contrivance, and its effect is to sanction and perpetuate divisions (which is to sanction schism under the false pretence of unity--RB), and to mar the prospect of an ultimate happy union in the church of Christ." Biblical union and uniformity is shown to be based on "agreement in doctrine, worship, discipline, and government."

Moreover, the author contends that, "this is to be constantly sought after by men united in mind and heart, pledged to God and to one another; it is to be externally manifested, and to be diligently labored for, that it may be generally and universally prevalent. It is never to be viewed as impracticable.

This was the main design of the convocation of the Westminster Assembly." The eschatological aspect of visible unity is also noticed, shedding valuable light on such postmillennial strongholds as, "The watchmen on the walls of Zion shall see eye to eye, they shall lift up the voice together, and together shall they sing" (Isa. 52:8) and "The Lord shall be King over all the earth; in that day there shall be one Lord, and His name one" (Zech. 14:9).

This book is full of faithful encouragement and is one of the best introductions to this topic we have seen.