John 17: 21a May they all be one, as You, Father, are in Me and I am in You. (HCSB)
The Stone - Campbell Union
Two groups of restoration-minded Christians came together in 1832.
Alexander Campbell had been seeking to bring about the vision his father Thomas had articulated in his Declaration and Address of 1809. Working for reforms within the Baptist church for two decades, Campbell called for a restoration of the "ancient order". There was significant resistance to some of his teachings (particularly regarding the role of the the Old Testament and the Ten Commandments in Christian doctrine.) The so-called Baptist Reformers were finally pushed out of the Baptist fellowship beginning in 1829. Due to the autonomous nature of the Baptist churches, this happened in isolated places at first, and spread until by 1832 the Baptist Reformers were completely separate. These reformer congregations continued to associate with each other, and diligently preached the "ancient gospel" and calling people to the "ancient order." To avoid creating a new party named after a person (as the Lutherans and Wesleyans) or a characteristic doctrine (as the Baptists and Presbyterians,) they chose the name Disciples of Christ. For similar reasons, Campbell ceased publishing the Christian Baptist and began a new paper, the Millennial Harbinger.
The second group was led by Barton Stone. Stone had broken away from the Presbyterian church in 1803, and began calling believers to unite under the name "Christians" upon the Bible alone. He formed congregations throughout Ohio and Kentucky.
As the Disciples and the Christians went about preaching in the same territory, they naturally encountered one another. They found that they held many of the same convictions, and began to associate informally. But there was one difference in their doctrine. The Disciples held that a person must be baptized for the forgiveness of their sins in order to enter the fellowship of believers. The Christians taught baptism for forgiveness of sins, but they received new members simply by giving "the right hand of fellowship," and left it up to each one to decide whether to be baptized. The two leaders held each other in high respect, and communicated on more than one occasion about the possibility of a union between the two groups. Campbell had significant influence on Stone in bringing him around on the key topics of difference.
Meanwhile, the members of the two groups continued to associate with one another at every opportunity. Then in January 1832, representatives of the two movements (John "Raccoon" Smith from the Disciples, and Barton Stone from the Christians) met in Lexington to discuss a union. They agreed to unify based on the Bible and the Bible only. They were not concerned about their different opinions on various topics, and agreed not to make those opinions a condition of fellowship. The two groups in attendance became one that day, and went out to take the message of union to the other congregations.
Maybe we can do that again one day.