Most of the difficulties encountered in putting into practice the reform of the Liturgy and especially the reform of the Mass stem from the fact that neither priests nor faithful have perhaps been sufficiently aware of the theological and spiritual reasons for which the changes have been made, in accordance with the principles laid down by the Council.
Priests must acquire an ever deeper understanding of the authentic way of looking at the Church,(38) of which the celebration of the Liturgy and especially of the Mass is the living expression. Without an adequate biblical training, priests will not be able to present to the faithful the meaning of the Liturgy as an enactment, in signs, of the history of salvation. Knowledge of the history of the Liturgy will likewise contribute to an understanding of the changes which have been introduced, and introduced not for the sake of novelty but as a revival and adaptation of authentic and genuine tradition.
The Liturgy also requires great balance, for, as the Constitution Sacrosanctum concilium says, it "is thus the outstanding means by which the faithful can express in their lives, and manifest to others, the mystery of Christ and the real nature of the true Church. It is of the essence of the Church that she be both human and divine, visible and yet invisibly endowed, eager to act and yet devoted to contemplation, present in this world and yet not at home in it. She is all these things in such a way that in her the human is directed and subordinated to the divine, the visible likewise to the invisible, action to contemplation, and this present world to that city yet to come, which we seek."(39) Without this balance, the true face of Christian Liturgy becomes obscured.