In commenting on Isaiah 2:4 (“neither shall they practice war anymore”), John Calvin writes that the reconciliation of men with God should lead to the reconciliation of men with men. Insofar as Christ’s kingly power is acknowledged, so far shall we be able to live at peace with one another.
And yet we only make a beginning of this in this life, and make it so very imperfectly. We should therefore pray that Christ will reign in us more and more, seek to make progress in submitting to Christ’s rule, and, “cultivating mutual friendship,” strive to be at peace with all men.
It may be objected that, in a state of harmony and peace, the sword will no longer be needed. I reply, that peace exists among us just as far as the kingly power of Christ is acknowledged, and that these two things have a mutual relation. Would that Christ reigned entirely in us! for then would peace also have its perfect influence. But since we are still widely distant from the perfection of that peaceful reign, we must always think of making progress; and it is excessive folly not to consider that the kingdom of Christ here is only beginning. Besides, God did not gather a Church — by which is meant an assembly of godly men — so as to be separate from others; but the good are always mixed with the bad; and not only so, but the good have not yet reached the goal, and are widely distant from that perfection which is required from them. The fulfillment of this prophecy, therefore, in its full extent, must not be looked for on earth. It is enough, if we experience the beginning, and if, being reconciled to God through Christ, we cultivate mutual friendship, and abstain from doing harm to any one.