John 17 is a prayer of Jesus. Much of it is a prayer that Jesus’ followers would be one, or united. Christian groups that began as unity movements were inspired by this prayer. This includes the Christian Church (Disciples of Christ).
Under the leadership of Barton Stone the Christians in Kentucky began in 1804. Stone would state their goal of unity for all Christians in sayings like, “We are Christians only but not the only Christians.” and “Unity is our polar star.”
In 1809, Thomas Campbell published The Declaration and Address of the Christian Association of Washington (Pa.). This is considered the beginnings of the Disciples in western Pennsylvania. In it Campbell states “That the Church of Christ upon earth is essentially, intentionally, and constitutionally one.”
As followers of these two unity movements came to know of the other group they began to ask “why aren’t we together?” The leaders met and decided to become one group, following the saying “In essentials unity, in non-essentials liberty, in all things love”. Unfortunately in later generations leaders rose who saw some issues that the original leaders saw as non-essential as being essential, which led to divisions.
About 50 years ago the Jesus People Movement started and it had some elements of wanting Christian unity as can be heard in this song by Love Song, also inspired by John 17, Let Us Be One.