Joseph Smith and Oliver Cowdery — The Voice of the Lord in the Chamber of Father Whitmer

While at the home of Peter Whitmer Sr. in Fayette, New York, Joseph Smith and Oliver Cowdery sought the Lord in prayer to understand how and when they should exercise the Melchizedek Priesthood authority they had received. In response, the voice of the Lord came to them in the chamber, commanding them to ordain each other to the office of Elder, but instructing them to defer this ordination until the baptized believers could assemble and give their common consent. This divine communication provided the specific procedural direction for the formal organization of the Church.

Fuller account of this event (as retold in Peter Whitmer Home and Farm, Fayette, New York, BYU Journeys):

Most likely, it was also in this bedroom that the Prophet Joseph Smith and Oliver Cowdery heard the voice of the Lord directing them how to organize the church of Christ (see D&C 20:1; 128:21). After all those present sustained Joseph Smith Jr. and Oliver Cowdery as their teachers. After Joseph and Oliver ordained one another to the office of elder, they administered the sacrament of bread and wine to those present.