Not infrequently the concern for unity (both ecumenical and social) and the concern for mission are played off against each other among Pentecostals. In this article it is argued that these two topics neither oppose each other nor do they simply reflect the two sides of the same coin. Rather, the Missio Dei precisely is to bring back to unity all aspects of life in a world suffering from division and alienation. By analyzing the relation of mission and unity in some of the New Testament books, it is argued that the mission of the church is inseparably linked to the topic of unity; division cannot take place without harming the church's mission to be a visible demonstration of God's renewing power in this world. Some concluding implications for a Pentecostal theology of missions are outlined.