This unity is that which is resultant from the indwelling and dominating control of the Holy Spirit. The illustration is that of the head and the body. Every limb or member or faculty of the body is controlled by the nerve system, and this nerve system works from and to the head, where it has its base.
In the Body of Christ, the Holy Spirit is the great nerve system, and only as there is an immediate response to every intimation of the will of the Head, and the life is unbrokenly in correspondence with His mind, can there be the unity of which the New Testament speaks.
Three things must be clearly noticed. (1) We cannot "keep" what does not exist. The admonition presupposes our having received the Holy Spirit into our lives in a vital way, and having surrendered ourselves entirely to His control and direction. (2) We cannot create this unity. It is essentially spiritual. Creeds, organizations, the social spirit, compromise on matters of interpretation, can never achieve it. (3) There is the paradox of unity. "Peace" in the Scriptures means harmony. But while Christ is called "the Prince of Peace," and while that harmony has been created in many lives and spheres where He has been enthroned, He clearly said that one result of His coming would be, not peace, but the sword.
It is clear that, wherever His Cross has been fully presented, there has been trouble and upheaval. All the things against which His Cross stands have at once created a state of war. The world and the flesh, in all their forms and expressions, make spiritual unity impossible, and to the extent that Christians are influenced in their judgments, their standards of reckoning, their conceptions, as well as their methods and means and motives, by the world spirit or the "Adam" nature, true spiritual unity is so far impossible.
The fuller the presentation of the Cross, the greater the arousing of the fallen nature elements, and therefore, on the one hand the greater the peril and possibility of discord, and on the other hand, the call for a more complete capitulation to the life of the Spirit as against the life in the flesh.
This work of separating will be carried out in ourselves personally, in our homes, in our local churches and in Christendom at large. On the basis of "flesh and spirit," the "house divided against itself" will fall.
True unity has its birth at Calvary, where the world, the flesh – with the devil working through both to maintain his discord in the universe – were dealt with and for ever ruled out of the New Creation.
It is this unity, which Calvary creates, which is the call for our diligence for its maintenance. This diligence must take the form of an earnest watch on the part of every member of Christ's Body against discordant elements, and a stolid refusal to be disaffected towards another member by anything short of a positive and persistent resistance of the purposes of Calvary.
First published in "A Witness and A Testimony" magazine, March-April 1946, Vol 24-2