In Invitation to World Missions (Tennent, 2010), Tennent notes that until the 16th century, the term mission was used to speak exclusively of the doctrine of the Trinity. In the 16th century, however, the Jesuits began using it to also refer to the obligation to propagate the gospel to parts unknown. Since this time, mission and missions has steadily weighted toward anthropocentric terms, and in many circles broadened past the scope of what should be included in a biblical understanding of mission. Invitation to World Missions (Tennent, 2010), 54.
In response to this, a reaction has occurred in missional theology that attempts to reclaim a focus on God as the center and source of mission. In the middle of the 20th century, ecumenical conversations took a focus on the missio dei in a direction that untethered it from the church. In an attempt to focus again on God's role in mission, these conversations suppressed the church's role, to the point of prioritizing God's work in the world everywhere except within the church.
Rightly, evangelicals in the decades since have attempted to elevate the conversation about the missio dei while noting the importance of His church in that mission. For Tennent, this means a God-centered but church-focused mission.Invitation to World Missions (Tennent, 2010), 59. This attempt to hold these two ideas together led to a common distinction between mission, or the larger work of God from creation to recreation, and missions, or the range of activities that the church does to participate in God's mission. While this distinction itself is often defined in different ways (see Peters for the origination of the distinction, Moreau, Goheen, and Wright who make both about the church), it can be helpful for organizing our understanding of the Biblical account of mission.
Another common way to conceive of this distinction is to discuss the mission of God and the mission of the church, or the mission of God's people. This is the approach that Christopher Wright uses with his two books, The Mission of God and The Mission of God's People. A Biblical Theology of Mission is best discussed by considering first the mission of God himself and subsequently the mission of the church as it exists within the broader purposes of God. On this point, Wright's distinctions are rather helpful.