6 In the face of the firm and generous resistance of the oppressed, the Government now began to give indications in various ways that it would not be averse to coming to an agreement, if only to put an end to a condition of affairs which it could not turn to its own advantage. Whereupon, though taught by painful experiences to put scant trust in such promises, We felt obliged to ask Ourselves whether it was for the good of souls to prolong the suspension of public worship. That suspension had indeed been an effective protest against the arbitrary interference of the Government; nevertheless, its continuation might have seriously prejudiced civil and religious order. Of even greater weight was the consideration that this suspension, according to grave reports which We received from various and unexceptionable sources, was productive of serious harm to the faithful. As these were bereft of spiritual helps necessary for the Christian life, and not infrequently were obliged to omit their religious duties, they ran the risk of first remaining apart from and then of being entirely separated from the priesthood, and in consequence from the very sources of supernatural life. To this must be added the fact that the prolonged absence of almost all the Bishops from their dioceses could not fail to bring about a relaxation of ecclesiastical discipline, especially in times of such great tribulation for the Mexican Church, when clergy and people had particular need of the guidance of those "whom the Holy Ghost has placed to rule the Church of God."
Source: Acerba Animi (Vatican.va)