Thomas and Alexander Campbell and Barton Stone were all ex-Presbyterian ministers who had been influenced by reformers in Scotland, specifically John Glas, Robert Sandeman (Glas's son-in-law) and Robert and James Haldane. Glas (1695-1793) became known as the founder of the 'Scotch Baptists' becaused they practised adult baptism by immersion. An ordained minister in the Presbyterian church, Glas was determined early on to make the Word of God his sole rule of conduct. When he began preaching a series of lessons from the Shorter Catechism (Presbyterian Manual) he noted there were strong differences in it from the Bible.
He came to realise that the church was composed of those who had experienced the grace of Christ, had separated themselves from the world and gathered themselves in the church. He could see no place for State involvement in church affairs, and this brought him into conflict with the Civil authorities. In 1725 he started an independant church which he called a Society of Believers.
His teaching was regarded as close to treason and Glas was brought before a number of synod meetings before being suspended as a minister and deposed from the church ('the right boot of disfellowship'). However, in 1739 the General Assembly broke precedence and revoked the sentence of deposition and restored Glas as a minister, although it didn’t restore his licence as a minister of the church of Scotland. He was allowed to continue in ministry with independant churches. This showed a sign of softening of their stand against Congregationalism. With the assistance of his son-in-law the message spread and churches sprang up all over
Sandeman migrated to North America where he established a church which later joined the Restoration Movement.