Peter J. Leithart is president of the Theopolis Institute, a Christian think tank and training center based in Birmingham, Alabama.

On Earth as in Heaven calls the church to embrace her identity and mission as one shaped by biblical theology and liturgy. The world grows increasingly polarized and politicized, but the church's commission remains unchanged. Christians carry out Jesus's mission by being the church. To change the world, the church needs only to be what she is--the bride of Christ--and to do what she does--teach, preach, sing, pray, break bread. Cultural and political mission and individual witness and service all spring from the church's liturgical life. As the church proclaims God's word and practices vibrant liturgy, she is God's heavenly city, shining as a light to the world.