In an age of deconstruction and rethinking, the Church should not be surprised to find itself confused by words like mission, missions, and missionary. Some struggle to redefine these categories and some seek to reclaim them, while others reject them outright, with or without providing new terms to guide us forward.

But words and their meaning matter; our confusion has a cost. Competing priorities pressure us to stretch our mission definitions as wide as they can go, releasing our people to creatively engage in service of every description. Some churches turn away from traditional...