5 Moreover, We trust that Our exposition of the doctrine of the Mystical Body of Christ will be acceptable and useful to those also who are without the fold of the Church, not only because their good will toward the Church seems to grow from day to day, but also because, while before their eyes nation rises up against nation, kingdom against kingdom, and discord is sown everywhere together with the seeds of envy and hatred, if they turn their gaze to the Church, if they contemplate her divinely-given unity - by which all men of every race are united to Christ in the bond of brotherhood - they will be forced to admire this fellowship in charity, and with the guidance and assistance of divine grace will long to share in the same union and charity.
Source: Mystici Corporis Christi (Vatican.va)