There has been a long tradition which sees the mission of the Church primarily as obedience to a command. It has been customary to speak of the "missionary mandate." This way of putting the natter is certainly not without justification, and yet it seems to me that it misses the point. It rends to make mission a burden rather than a joy, to make it part of the law rather than part of the gospel. If one look at the New Testament evidence one gets another impression. Mission begins with a kind of explosion of joy. The news that the rejected and crucified Jesus is alive is something that cannot possibly be suppressed. It must be told. Who could be silent about such a fact? The fallout from a vast explosion, a radioactive fallout which is not lethal but life giving. One searches in vain through the letters of St Paul to find any suggestion that he lays it on the conscience of his readers that they ought to be active in mission. For himself it is inconceivable that he should keep silent. "Woe to me if I do not preach the gospel!" (1 Cor 9:16). But nowhere do we find him telling his readers they have a duty to do so.
Leslie Newbigin, The Gospel in a Pluralist Society, 1989, p116