Elders provide the governance backbone of the church. The Presbyterian Church Book of Order defines the role of a ruling elder and the qualifications of those called to serve in this capacity; it states that
ruling elders, together with teaching elders (pastors), exercise leadership, government, spiritual discernment, and discipline and have responsibilities for the life of a congregation as well as the whole church, including ecumenical relationships. When elected by the congregation, they shall serve faithfully as members of the session.
and that those who undertake particular ministries, including ruling elders
should be persons of strong faith, dedicated discipleship, and love of Jesus Christ as Savior and Lord. Their manner of life should be a demonstration of the Christian gospel in the church and in the world.
(The PC(USA) Book of Order)
The congregation, through a nomination and election process, identify candidates for various elder offices. A ruling elder serves in that capacity for a term of three years. Depending on the particular office held, elders are expected to understand the time and task requirements which they are committing themselves to while being an elder.