Incorporating children in worship is a powerful and overlooked mark of God's kingdom. This book argues that children's full participation in worship signifies not only a vibrant, faithful communion but also offers a critical window into the Spirit's work of linking the church to Christ. Children have a vocation in worship. They embody the theological virtues in distinct ways that enrich the worship of the whole church. Moreover, incorporating children reflects the difference in unity that is God's triune life. Receiving children in their difference moves the worshipping body toward the telos of worship--glorification of God and sanctification of humanity--and habituates the worshipping body to incorporate other, often more threatening, kinds of difference.