NOTES for Th1 5:12-28
As he concludes his letter to the Thessalonian Christians, Paul calls them to preserve the life of the Kingdom in which they have come to share. As is clear, it can be preserved only by remaining inhabitants of the Kingdom, which is what the apostle calls the recipients of his letter to do. Paul considers the main goal of all the spiritual efforts of the faithful to be the preservation of that spiritual wholeness without which life in the Kingdom is impossible and which must be carried through to the day of Judgment and the Savior's return (v. 23). And in order to preserve it, what is needed first of all is openness to the world, readiness to receive it and to "test" it (v. 21). Indeed, the task of the faithful is to carry the Kingdom into the world, and self-isolation is, of course, excluded in principle.
At the same time, however, in order to solve this task it is absolutely necessary to learn to distinguish good from evil and to make the right choice in the concrete situations of which life actually consists, so that each such situation would turn, for every faithful person, into a triumph of the Kingdom regardless of where and when it arose (vv. 21-22). And one can learn to live this way in only one way: by allowing that breath, or "spirit," of God that permeates the Kingdom to change one's human nature, making it fit for the new life. But such transformation will be impossible unless God is given the freedom He needs, freedom of access to the human heart, including in particular in the assemblies of the faithful, which in fact exist in order to become centers of this spiritual work. That is why the apostle calls them "not to quench the Spirit" and "not to despise prophecies" (vv. 19-20): for it is precisely in such forms that the action of God directed toward the transformation of human nature most often manifests itself.
But this work, like almost everything connected with a person's spiritual life, is a God-human work, and therefore God's action alone is not enough here. What is also needed is the environment in which the results of such action can be preserved and take root. In the apostle's thought, the Church must become that environment where those seeking new life can not only come to share in the Kingdom, but also live in it, building their relationships with God and with their neighbors according to the laws of the Kingdom, and not according to the laws of our still untransformed world (vv. 14-18). And then the Church will become what Christ Himself conceived and created it to be: a community of people living in the Kingdom and carrying it into the world.