What experiences, classes, books, and the like have shaped you and your ecclesiology? I was on Cru (formerly Campus Crusade for Christ) staff for 18 years at the University of Notre Dame and also in Italy, the Italian-speaking part of Switzerland, and other assignments, so I have significant parachurch experience. I also have broad experience in various types of churches: Evangelical Free, Swiss Evangelical Baptist, Conservative Baptist, and now, while at Southern Seminary, several Southern Baptist churches. Throughout the years I've served in various leadership capacities in these churches: co-pastor, chairman of the board of deacons, elder, and the like. All of these churches and leadership opportunities have shaped me and my ecclesiology. For the past four years I've been deeply involved in Sojourn Community Church, where I've served as a community group leader, a coach for several community groups, and a neighborhood pastor working with about a dozen such groups to help them be missionally oriented so as to reach portions of East Louisville with the gospel. Along with 35 other men, I'm part of Sojourn's council of elders serving four campuses in Louisville. This responsibility involves shepherding, teaching, church discipline, mercy ministry, praying, and much more. Most recently, I became a theological strategist for the Sojourn Church Planting Network, so I do the theological assessment of potential church planters, serve as an external elder for a couple of new church plants, work on theological education, and help pastors in the network think and live theologically. What is thrilling for me personally is daily putting my ecclesiology into practice. How did writing your massive Historical Theology prepare you for and strengthen your writing of Sojourners and Strangers? While working on Historical Theology for 13 years I developed my writing voice and the discipline of writing. So when it came to doing Sojourners and Strangers, I was well prepared for what it takes to design, initiate, develop, edit, and conclude a large project. Historical Theology also gave me much background material with which to work as I tackled ecclesiological issues like the nature of the church, church government, baptism, the Lord's Supper, and the ministries of the church. I'm deeply indebted to the evangelical theological tradition to which I'm an heir, and this legacy has definitely shaped my ecclesiology. Why did you select the title Sojourners and Strangers? What about this title does the contemporary church need to hear? The title comes from Peter's description of the church:
But you are a chosen race, a royal priesthood, a holy nation, a people for his own possession, that you may proclaim the excellencies of him who called you out of darkness into his marvelous light. Once you were not a people, but now you are God's people; once you had not received mercy, but now you have received mercy. Beloved, I urge you as sojourners and exiles [strangers] to abstain from the passions of the flesh, which wage war against your soul. Keep your conduct among the Gentiles honorable, so that when they speak against you as evildoers, they may see your good deeds and glorify God on the day of visitation. (1 Pet. 2:9-12)This description is a beautiful and captivating vision of what the church as a gospel-focused, Christ-centered, missional community is called to be during its earthly pilgrimage on this earth. Did your mind change on a particular issue while writing this? If so, what and why? I wouldn't say my mind changed so much as now I have emphases concerning several topics I'd previously overlooked. This is probably because much of evangelical theology overlooks certain discussions when doing ecclesiology. So readers will see a lengthy prolegomena in my book, discussing issues such as the sufficiency of Scripture, the continuity and discontinuity between the Old and New Testaments, the prescriptive and descriptive witness of Scripture, and the church in its relation to the kingdom of God. Such an approach is almost unprecedented in ecclesiology books, but it's much needed before one can actually construct an adequate doctrine of the church. Additionally, I have a robust notion of church discipline, arguing it functions as a sign or harbinger of the divine eschatological judgment. I hope this concept in particular will be helpful to churches as they grasp the importance of exercising discipline. Further, I offer biblical and theological warrant for multisite churches, urge churches to baptize new Christians very soon after their conversion, and embrace the memorial view of the Lord's Supper while also advocating for the celebration of Christ's spiritual presence in this ordinance—which I urge should be administered frequently (weekly). Readers will also find practical wisdom about how to incorporate these doctrines into their churches, as I share from my involvement in different churches. In what ways is it important for pastors to have a carefully developed biblical ecclesiology? Much of what's available to help pastors today—articles, blogs, videos, and the like—is pragmatically driven advice about how to do church. That being the case, pastors go from one new approach to preaching and worship, or discipleship and pastoral care, to another. In my view, before pastors should worry about how to do church they must grasp the identity of a church—its nature and characteristics. With that biblical and theological vision of the church's identity firmly established, they can then engage their cities with the gospel, preach the whole counsel of God, foster missionality as a characteristic of the church and not just a program, disciple and discipline members, and all the rest. Sojourners and Strangers, therefore, begins with several chapters about what the church is and is to be, and it concludes with a conversation about the ministries of the church. That design was not accidental but intentional, as it fleshes out the answer to your question.