As T.F. Torrance would remind us, theological thinking must be scientific, i.e. faithful to the object in question. This is no different with respect to a theology of mission. But in order to do so, we must work, as it were, “from below”, from the level of our hearing of the voice of Christ in the word of the gospel and working up from there. This is the way in which we come to know of the mission of the church in the first place, and so it is here that we must begin in order to develop a missiology that does not require from the start concepts foreign to the gospel to get off the ground.
The word of the gospel is the foundation of a scientific missiology. This is so because it is the means by which the Lord and Savior of the church, Jesus Christ, commanded his followers to carry out their commission. In Acts 1:8, Jesus states that his disciples are to be his witnesses to the ends of the earth. They are his witnesses — which means that they must discharge their mission in submission to the Lord who sent them — and they are his witnesses — which means they must do so by announcing the good news of what he has accomplished. Yet immediately after giving them this charge, Luke recounts that Jesus ascended into heaven and was hidden from their sight. The significance of this is elucidated by Torrance:
Jesus Christ has withdrawn Himself from sight, from on-going empirical history, withdrawn Himself from contemporaneous contact within history for reasons of mercy. Full manifestation of the risen Lord now in all His glory and majesty would mean the immediate end of this age, the end of the world, the final judgment…
Moreover, by withdrawing Himself from sight the ascended Lord sends the Church back to the historical Jesus, to the Gospel story of the incarnation, public ministry, death and resurrection as the only locus where He may be contacted. If Jesus had continued to be with His Church all through history as the contemporary of every generation, the Cross would have been relegated into the past and treated as a passing episode, and not as the fact of final and supreme and central import. The whole historical life and revelation of Jesus would have lost much of its significance. But He has veiled His present glory, so that if we would find Him we must go back to the historical Jesus. That is the only place where we may meet Him, but there we make contact with Him through the Cross at the point where the final act of God regarding sin has been accomplished. There is no other road to the Parousia of the risen Jesus, the Lord of Glory, except through the Jesus of Humiliation, the Jesus of Bethlehem and Judaea and Galilee and Calvary.
Of all aspects of the our present position in redemptive history, perhaps the most obvious fact is that its Lord is not physically visible in human history as he was prior to his ascension. Although it may seem strange to take the ascension as a starting point for a theology of mission, Torrance rightly emphasizes that “[t]he basic fact” of the apostolic witness and ministry which we encounter in the New Testament “is the Person of Jesus Christ, the risen Lord ascended to kingly rule over all in heaven and earth.” The ascension is, as it were, the gospel in present tense. While the events of Christ’s incarnation, death, and resurrection are past and his final advent is yet future, his ascended reign is ongoing even now, and thus it is with this basic fact — his apparent absence and final command to his disciples — that characterizes the present time and drives us to the task of defining the church’s role while it awaits its Lord’s return.
Moreover, as Torrance insightfully explains, the fact that the church heralds the reign of One who has hidden himself from view means that the church (and the world to which it witnesses) must continually return to the historical Christ of the gospel message in order to meet the ascended Christ. This is not to say, of course, that there are two Christs, but only that it is Christ’s own design that the saving import of his life, death, and resurrection be given the proper place that it deserves in the church’s witness. Lest his continuing bodily presence in his glorified state detract attention from the climactic events of his atoning work, he has withdrawn himself from view such that, as Torrance emphasizes, the cross becomes the place in which we may savingly encounter Christ ourselves and then lead others to him as well. This encounter thus occurs through the very witness with which Jesus charged his disciples just moments before his ascension.
Thus, in virtue of the “basic fact” of Christ’s ascension, the gospel message is, as stated above, the foundation upon which the church’s understanding of its gospel mission must be built. The church carries out its mission under the authority of the ascended Christ’s command, and that command constrains the church to constantly return to the message of the cross as the means by which that mission must be carried out. So what exactly is that message that serves as the foundation of the church’s understanding and practice of its mission? Torrance summarizes it as follows:
In His birth, life, death and resurrection Jesus Christ finished the work the Father gave Him to do. He the eternal Son and Word of God, by whom all things were made and in whom all things cohere, became flesh, a Man among men, incorporating Himself into the humanity He had made but which had alienated itself from God through sin. It was our corrupt human nature that He took upon Him, but in taking it and in living out His holy life in it, He condemned sin in the flesh and saved what He had assumed, healing and sanctifying the mother through whom He was born, the sinners with whom He identified Himself and to whom He communicated His grace, the company of men and women which He built around Him as His own body, loving them and giving Himself for them, and in them for all mankind.
In this oneness with us, wrought out in birth, in life and in death, He offered in Himself to the Father a sacrifice of obedience, bearing our judgment and offering us in Himself to the judgment of the Father, that through His life of obedience in our place where we are disobedient, and through His judgment in our place where we have no justification, He might destroy sin in our body of sin, death in our body of death, and raise us up in Himself to righteousness and new life, presenting us before God as those whom He had brothered and redeemed, and therefore as sons and daughters of the Father in Him.
In His resurrection and ascension, Jesus Christ was ‘raised up’ and ‘made to sit with God’ in heavenly places, that is, finally installed in His messianic office as the Christ enthroned as King and Priest and Prophet at the right hand of God. As Head of the Church, and of mankind, and Lord of all things, He rules from on high, ever lives as our Mediator and Advocate before God in the eternal power of His priesthood and sacrifice, and through the blessing of His Spirit poured out upon men sends forth His healing and creating Word for the reconciliation and recreation of mankind. He is the New Man, the New Adam, the New Creation, full of Life and life-giving power. It is through union and communion with Him actualised in the Spirit that the Church is quickened into life as His living Body on earth and is empowered in its apostolic mission to be His representative among men.
Now it is no accident that Torrance presented this gospel summary in the to his essay on “The Mission of the Church”. It is from this point, therefore, that we must move forward.
 T.F. Torrance, Conflict and Agreement in the Church, vol. 1: Order and Disorder (Eugene, OR: Wipf & Stock, 1996), 311.
 Ibid., 308.
 T.F. Torrance, “The Mission of the Church”, Scottish Journal of Theology, no. 19 (1966): 129-130.