Ubi Arcano Dei Consilio §55

⁵⁵ All these organizations and movements ought not only to continue in existence, but ought to be developed more and more, always of course as the conditions of time and place seem to demand. There can be no question of the fact that these conditions are at times very difficult and exact of both pastors and the faithful a great and increasing amount of sacrifice and labor. But since such work is vitally necessary, it is without question an essential part of our Christian life and of the sacred ministry and is therefore indissolubly bound up with the restoration of the Kingdom of Christ and the re-establishment of that true peace which can be found only in His Kingdom - "the peace of Christ in the Kingdom of Christ."