What's Wrong with the New Mass?
from "Vatican II, the Pope and the Mass" by Rev. Donald J. Sanborn.
Among other things, the liturgical changes of Vatican II reflect the doctrinal errors of the Council concerning: (1) the unity of the Church; (2) ecumenism; (3) religious liberty and (4) collegiality. (See What's wrong with Vatican II? FAQs)
The new liturgy is an ecumenical liturgy, and seeks to erase any doctrines which are distinctly Catholic, and to turn the Catholic liturgy into a form of worship which would not be offensive to any Protestant. It is man-centered worship, stripped of all symbolism of the supernatural.
The Ordo Missae of Paul VI is an evil liturgical discipline, because:
it contains a heretical definition of the Mass;
it was composed with the express purpose of making an ecumenical liturgy, pleasing to Protestants, stripped of Catholic truths concerning the priesthood, the Holy Sacrifice of the Mass, and the Real Presence of Christ in the Holy Eucharist;
it was composed with the help and input of six Protestant ministers, which shows the heretical spirit in which it was conceived and formulated;
its authors systematically deleted from its prayers and lessons doctrines which would be offensive to heretics;
it teaches, both by its omissions and by its symbolism and gestures, heresies and errors concerning the priesthood, the Holy Sacrifice of the Mass, and the Real Presence of Christ in the Holy Eucharist.
Furthermore, it is most probably invalid owing to a defect of intention which it causes in him who celebrates it, and owing, at least in the vernacular, to a blasphemous alteration of the words of Christ in the consecration formula.