The Relief Church issued no distinctive testimonies, and a certain breadth of view was shown in the formal declaration of their terms of communion, first made in 1773, which allowed occasional communion with those of the episcopal and independent persuasions.
In 1794, the Relief Church adopted as its hymn book Patrick Hutchison's Sacred Songs and Hymns on Various Passages of Scripture, and it was Hutchison who established the first systematic definition of the Relief Church's beliefs.
It was the first presbyterian body to relax the stringency of subscription, the Church Synod passing a declaratory act on the subject in 1879.
The United Presbyterian Church constructed a number of notable buildings, the largest of which often used a neoclassical design with a portico.
A particularly fine example is Wellington Church, near the University of Glasgow, which was built in 1883–84 by the architect Thomas Lennox Watson.
This preference for neoclassical architecture contrasts strongly with the prevailing mid-Victorian taste for Gothic Revival in most of the other Scottish churches.
Of the three, only St Vincent Street survives intact, Caledonia Road Church being an empty shell and Queen's Park destroyed by World War II bombing.
His architectural style was often eclectic; it cannot be described as truly neoclassical (he never managed to visit Greece), but he frequently used Egyptian and other Middle Eastern motifs.