Whole books have been written on this topic; an exhaustive treatment here is not possible. However, for brevity’s sake, Peter Kuzmic, missions professor at Gordon-Conwell Theological Seminary, proposes that several theological themes emerge in the Bible that form a theological basis for why we engage in world missions.

1. God of the Bible is a missionary God and the Church is God's missionary people.
2. Missions is at the center of God's divine purpose for the human race, not just something peripheral or added on. (Many theologians refer to this as Missio Dei.)
3. The Church of Jesus Christ is not the place that collects and conserves people for heaven that functions as a waiting room for the hereafter. The Church of Jesus Christ is God's transformative agent in the world.

Alan Hirsch adds: So a working definition of missional church is a community of God’s people that defines itself, and organizes its life around, its real purpose of being an agent of God’s mission to the world. In other words, the church’s true and authentic organizing principle is mission. When the church is in mission, it is the true church. The church itself is not only a product of that mission but is obligated and destined to extend it by whatever means possible. The mission of God flows directly through every believer and every community of faith that adheres to Jesus. To obstruct this is to block God’s purposes in and through God’s people.” (The Forgotten Ways, p. 82)

• Our overarching hermeneutic is a two-way journey between the text and the context, the Word and the world. (I.e., our presuppositions and methods for missions must take into account both Biblical principles, as well as the context in which they are applied.) [1]

George Peters adds: “the end result of missio Dei is the glorification of the Father, Son, and Holy Spirit.” (A Biblical Theology of Missions, p.9)

Resources for more in-depth study

Kaiser, Walter. Mission in the Old Testament: Israel as a Light to the Nations.

Peters, George, A Biblical Theology of Missions

Ott. Craig, Encountering Theology of Mission: Biblical Foundations, Historical Developments, and Contemporary Issues

The Perspectives Reader contains a section on the Biblical basis and theology of missions.

[1] https://www.biblicaltraining.org/theology-world-missions/peter-kuzmic

A Greater Commission: A Theology For World Missions