9 For these reasons We urge and exhort all who know and love this divine Heart willingly to undertake this act of piety; and it is Our earnest desire that all should make it on the same day, that so the aspirations of so many thousands who are performing this act of consecration may be borne to the temple of heaven on the same day. But shall We allow to slip from Our remembrance those innumerable others upon whom the light of Christian truth has not yet shined? We hold the place of Him who came to save that which was lost, and who shed His blood for the salvation of the whole human race. And so We greatly desire to bring to the true life those who sit in the shadow of death. As we have already sent messengers of Christ over the earth to instruct them, so now, in pity for their lot with all Our soul we commend them, and as far as in us lies We consecrate them to the Sacred Heart of Jesus. In this way this act of devotion, which We recommend, will be a blessing to all. For having performed it, those in whose hearts are the knowledge and love of Jesus Christ will feel that faith and love increased. Those who knowing Christ, yet neglect His law and its precepts, may still gain from His Sacred Heart the flame of charity. And lastly, for those still more unfortunate, who are struggling in the darkness of superstition, we shall all with one mind implore the assistance of heaven that Jesus Christ, to whose power they are subject, may also one day render them submissive to its exercise; and that not only in the life to come when He will fulfil His will upon all men, by saving some and punishing others, (St. Thomas, ibid), but also in this mortal life by giving them faith and holiness. May they by these virtues strive to honor God as they ought, and to win everlasting happiness in heaven.
Source: Annum Sacrum (Vatican.va)