The natural starting point for intercultural theological explorations of Western and African theology is the work of Andrew F. Walls. As Mark Noll writes, “no one has written with greater wisdom about what it means for the Western Christian religion to become the global Christian religion.” In particular, Walls has played a pioneering role in the study of African Christianity. According to Lamin Sanneh, “He is one of the few scholars who saw that African Christianity was not just an exotic, curious phenomenon in an obscure part of the world, but that African Christianity might be the shape of things to come.” Although he did most of his work before intercultural theology became “a thing,” he is in many ways an intercultural theologian par excellence. A lifetime of work on both the European and African continents has given him an unparalleled understanding of modern church history and contemporary Christianity in both contexts, and especially intercultural movements between the two. His life’s work has also deeply influenced his belief in the importance of intercultural theology and shaped his theoretical approach.
The first aspect of Walls’ approach is his biblical grounding of intercultural theology. In contrast to much of intercultural theology, which takes its starting point in recent trends in Western scholarship or the growth of Christianity in the Global South, Walls sees the grounds for intercultural theology as lying primarily in the Christian Scriptures. In his lecture on “The Ephesian Moment,” he explores the cross-generational and cross-cultural nature of redemption. Drawing on the Hebrews 1:1-2, he underlines the fragmentary nature of God’s self-revelation in history until, in the fullness of time, God revealed Himself fully in the person of His Son. Yet Jesus’ incarnation, life, death, resurrection, ascension and outpouring of His Spirit on his disciples were not the end of the historical process of redemption. The Old Testament heroes of faith in Hebrews 11 “did not receive what was promised, since God had provided something better for us, that apart from us they should not be made perfect.” The author of Hebrews realised that their stories were incomplete without the stories of those who came after them, and the same is true today. The whole company of faith, spread out through time and space – terrible as an army with banners – is part of a single story awaiting its summation in Christ.
Turning to Ephesians, Walls further explores the church’s temporal and spatial dimensions. The remarkable growth of Christianity among the Gentiles in the ancient Mediterranean raised serious questions for the early church. Would the Gentile movement to Christ result in a church characterised by separate meal tables divided along ethnic and cultural lines? The answer in Ephesians is a resounding no. The metaphor of building a temple in Ephesians 2 and the beautiful trinitarian expression that accompanies it implies the construction of a unity of human diversity in Christ, a house for God, through the work of the Holy Spirit. In Ephesians 4 the metaphor dramatically shifts to the building up of a body, which is to grow “until we all attain to the unity of the faith and of the knowledge of the Son of God, to mature manhood, to the measure of the stature of the fullness of Christ.” Paradoxically the coming together of human diversity in Christ results in common faith and understanding which grows the church in maturity and stature. Ultimately, as Walls writes,
Christ’s completion…comes from all humanity, from the translation of the life of Jesus into the lifeways of all the world’s cultures and subcultures through history. None of us can reach Christ’s completeness on our own. We need each other’s vision to correct, enlarge, and focus our own; only together are we complete in Christ.
Walls’ biblical grounding of intercultural theology reveals three further aspects of his theoretical approach.
The second aspect of Walls’ approach is his Christocentric focus. Christian salvation depends on the historical person and work of Christ. Thus, the central focus of theology is: “understanding who Christ is and why he is so called.” The primary concern for the early church how to articulate who Jesus was and what he meant to Greek-speaking Gentiles. Talking about Jesus using the Jewish title ‘Messiah’ was problematic because Gentiles were unfamiliar with the term, so they translated it into the Greek title ‘kyrios’, which meant “Lord.” The translation was a key move and not without risks, yet rather than distorting the early church’s understanding of Jesus it was enriching, with important implications for both Christology and Trinitarian theology. Not only was he the Messiah, with all the rich meaning that term carried, “Crossing a cultural frontier led to a creative movement in theology by which we discovered that Christ was the eternally begotten Son.”
Closely connected with Wall’s Christocentric focus is his emphasis on catholicity. As Walls states, “The church must be diverse because humanity is diverse; it must be one because Christ is one.”God reveals Himself to a diverse company of faith that is being built together into a temple where God dwells, into a body that demonstrates Jesus’ life to the watching world. “The Ephesian moment – the social coming together of people of two cultures to experience Christ—was quite brief….But in our own day the Ephesian moment has come again, and come in a richer mode than has ever happened since the first century.”Only together can we grow in our unity of faith and understanding of who Jesus is. Only together can we hope to attain to “the measure of the stature of the fullness of Christ.”
The fourth aspect of Walls’ approach is his eschatological vision. God has already revealed Himself fully in the person of His Son, but the fullness of God’s self-revelation in Jesus has not yet attained its summation. Similarly the Holy Spirit has already brought the church into being, but the body of Christ has not yet reached its full stature. As Walls asserts, “The work of salvation is a historical process that stretches out to the end of the age.” The end of the age “is not a sudden act of divine despair that abandons the process on earth as useless….Equally, the end of the age is not…a sort of evolution in which the heavenly kingdom grows naturally out of a set of conditions achieved on Earth.” There is no room for either end times despair or chronological snobbery in intercultural theology. The Ephesian moment is a foretaste of the great multitude that no one can number in Revelation 7, the fullness of Jesus’ humanity in all its diverse cultural forms.
 Mark A. Noll, “Andrew F. Walls: The Missionary Movement in Christian History (1996),” First Things, March 2000, accessed 8 December 2015, http://www.firstthings.com/article/2000/03/andrew-f-wallsthe-missionary-movement-in-christian-history.
 As quoted in Tim Stafford, “Ahead of His Time: Andrew Walls May Be the Most Important Person You Don’t Know,” Christianity Today 51, no. 2 (February 8, 2007): 87, http://www.christianitytoday.com/ct/2007/february/34.87.html.
 See Volker Küster, “Toward an Intercultural Theology: Paradigm Shifts in Missiology, Ecumenics, and Comparative Religion,” in Theology and the Religions: A Dialogue, ed. Viggo Mortensen (Grand Rapids, MI: Wm. B. Eerdmans, 2003), 171–84 and “The Project of an Intercultural Theology,” Svensk Missionstidskrift 93, no. 3 (January 1, 2005): 417–32; and especially Werner Ustorf, “The Cultural Origins of ‘Intercultural Theology,’” Mission Studies 25, no. 2 (January 1, 2008): 229–51.
 See Philip Jenkins, The Next Christendom: The Coming of Global Christianity, 3rd ed. (New York: Oxford University Press, 2011) and The New Faces of Christianity: Believing the Bible in the Global South (Oxford: Oxford University Press, 2006).
 Although Walls does not explore it here, the emphasis on the spoken nature of revelation in the introduction of the Letter to the Hebrews has a lot of potential for intercultural theology.
 Andrew F. Walls, The Cross-Cultural Process in Christian History: Studies in the Transmission and Appropriation of Faith (Maryknoll, NY: Orbis, 2004), 72.
 Hebrews 11:39-40 ESV.
 Walls, The Cross-Cultural Process in Christian History, 73.
 Ibid., 74.
 Ephesians 4:13 ESV.
 Walls, The Cross-Cultural Process in Christian History, 78.
 Ibid., 72.
 Walls, The Cross-Cultural Process in Christian History.
 Ibid., 79–80; for more on translation as a key theme in contextualization, see Lamin O. Sanneh, Translating the Message: The Missionary Impact on Culture, 2nd ed. (Maryknoll, NY: Orbis Books, 2009).
 Walls, The Cross-Cultural Process in Christian History, 80.
 Ibid., 77.
 Ibid., 78.
 Ibid., 73.
 Walls, The Cross-Cultural Process in Christian History.