The cross was emptied and so was the tomb. But Pentecost reminds us that this emptiness speaks not of a vacuum left for the filling up of our piety and our proclamation but of the filling of the Church with the Spirit of the risen Lord. The emptiness of the cross before us is not one to be filled with timeless truths and moral principles but with the fellowship and decisiveness of a prayerful people thrown daily at the mercy of the promised presence and guidance of a living Lord.
We best be careful not to turn an evangelical strength into a weakness by so emphasizing the cross of Christ that we drain it of its power. I mention this because I think it is far too common for Christian churches to recede into a merely proclamational stance rather than take up the call to make concrete theological decisions (and act on them) together in the prayer for Kingdom come. Barth says it better than I have:
The community may very well forget that it has to hear and attest Jesus Christ as the Lord who is risen again from the dead and therefore lives as the Prophet of God who in the power of the Holy Spirit is not inactive but powerfully at work in the time between Easter and His final appearing both in heaven and on earth. On its own lips the eternal Word from His lips may well become timeless truth. The concrete meaning with which it speaks here and now may well dissolve in its presentation into an abstract signification. The specific point with which His Gospel, notwithstanding its identity in every age and therefore its universality, penetrates each specific historical situation with a specific intention to be specifically received and attested by the community, may be softened and blunted and secretly broken off or rendered invisible in its proclamation. The Gospel as transmitted by it may be changed into a dull impartation which says everything and nothing, proclaiming a supposed but not a real salvation.
Formally, such an impartation need not be lacking in a biblical foundation, biblical content and attachment to the best traditions of the ecclesiastical past, such as, for example, those of the century of the Reformation. It can have the appearance of a true message of Christ, a true preaching of the kingdom of God or true praise of free grace. It can ostensibly be a proclamation of justification by faith alone and a warming reference to the spiritual conversion and moral renovation needed by humanity.
And why should it not proclaim this with genuine emotion and true zeal? In this corrupted form only one thing will be carefully left out and therefore lacking. The impartation will not be intended nor go forth as an invitation to or demand for a concrete decision of faith and obedience, at any rate in the sense of a Yes or No which entails a distinction of word and act at a specific time and in a specific situation. In spite of all its profundity and eloquence, at the point where it ought to do this, it will come to a halt and become an inarticulate mumbling of pious words.
There will be talk of inward regeneration by faith, of the struggle for a new awakening by the Spirit of God, of the solemn prospect of a distant “world of Christ,” but there will be no demand to grasp the nettle and to make a small beginning of this regeneration and awakening in a specific act of will here and now. There will be prayer for peace, but prayer committing no one. When the time comes for steps to peace which commit anyone, there will be quick withdrawal into neutrality, into a safe avoidance of the fatal problems and the even more fatal freedom from problems of the existing present, followed by a new and powerful and sincerely meant but blunted and generalised and therefore impotent assurance that Jesus Christ is risen, that He will come again at the last day and put everything right, and that faith in Him is the victory which overcomes the world.- Karl Barth, Church Dogmatics IV/3.2, 813-814