As a professor of theology and a minister in the church, I take seriously James’s warning that teachers “will be judged more strictly” (Jas. 3:1, NIV). Something has to distinguish authentic Christian belief from the host of other religions and ideologies, and the preservation of the gospel requires opposition to certain beliefs and practices. For my part, I maintain that authentic Christian belief is rooted in the historic Christian vision of God as Father, Son, and Holy Spirit and what this God has done for the redemption of all creation, including the incarnation and resurrection of God’s Son, Jesus Christ.As important as these shared beliefs are, however, there is something more fundamental to unity. In fact Christians can agree on matters of belief and practice and still be divided by race and ethnicity, social status, political convictions, musical preferences, and even petty slights. More fundamental than our religious convictions and social identity markers is our union in Christ (Gal. 3:26-28) and the shared Spirit (1 Cor. 12:13), which God has graciously given to us in our baptism. Further Jesus’s followers must have a heart that desires and pursues unity. A spirit of authentic unity is possible only by God’s Spirit of unity working in us.In Ephesians 4:1 Paul calls Christians to “live a life worthy of the calling you have received.” English translations usually translate 4:2-3 as a series of imperatives or commands, but these verses are actually prepositional phrases and participles that expand upon and describe the “life worthy of the calling you have received.” This way of life includes being humble and gentle, being patient, bearing with one another in love, and making “every effort to keep the unity of the Spirit though the bond of peace” (4:2-3). Christian unity is a gift of the Spirit, but it is also something Christians are called to pursue. Just as Christians are to grow in the virtues of humility, gentleness, patience, and love, so Christians are to desire and develop a spirit of unity.A spirit of unity, like the rest of the Christian virtues, is “the fruit of the Spirit” in our lives. In other words, a spirit of unity is evidence of the Spirit’s presence and working in us. It is interesting to consider both “the acts of the flesh” and “the fruit of the Spirit” in Galatians 5 in regards to Christian unity. The acts of the flesh include things like “hatred, discord, jealousy, fits of rage, selfish ambition, dissensions, factions, and envy” (5:20-21). In other words divisiveness is a destructive sin that comes quite easily to us and regularly tempts us. The acts of the flesh are contrasted with the fruit of the Spirit, which includes virtues that, among other things, cultivate unity in the church: “love, joy, peace, forbearance, kindness, goodness, faithfulness, gentleness, and self-control” (5:22-23). The Spirit of unity gives the virtues needed to pursue and maintain unity to those who humbly seek God.Like the rest of Christian discipleship, the pursuit and maintenance of unity is beyond our natural capabilities and inclinations. We need God’s Spirit to help us grow in wisdom as we discern which beliefs and practices are fundamental and spiritually healthy, and which are not. We need God’s Spirit to give us ears to hear God’s truth, especially when it comes from our opponents, and mouths that speak the truth in love. We need God’s Spirit to help us desire peace and love the unlovable. Christian unity is possible only by the power of the Spirit who binds the church together as one.Even more so than a rigid uniformity, a spirit of unity among Christians is crucial for the proclamation of the gospel. An institutional unity preserved by power is far less compelling than a spirit of love even in the midst of visible divisions. After all, maybe God allows the divisions that exist, even among those who call on the name of Jesus, to help us grow in maturity and rely on God rather than our own schemes. Still, God calls us to pursue peace with others and submit to the Spirit’s work in our lives. As we do we live in hope, longing for the day when God gathers his people together as one, and the unity we already have in Christ is experienced in full.May the God who gives endurance and encouragement give you the same attitude of mind toward each other that Christ Jesus had, so that with one mind and one voice you may glorify the God and Father of our Lord Jesus Christ (Rom. 15:5-6).--------------------Mark Powell is professor of theology at Harding School of Theology in Memphis, Tennessee. His latest book is Centered in God: The Trinity and Christian Spirituality.