"Progressive" Catholics Are Heterodox Catholics

To speak of the Church using political labels is a fatuous pursuit. You are either faithful to the teachings of the Church or you are unfaithful. Public opposition to the Magisterium is dissent. Then Joseph Cardinal Ratzinger, as prefect of the Congregation for the Doctrine of Faith observed, "These doctrines require the assent of theological faith by all members of the faithful." The quotes below show that being a disciple of Christ requires total fidelity to Christ and Christ's Church.

The teaching Church does not invent her doctrines; she is a witness, a custodian, an interpreter, a transmitter. As regards the truth...she can be called conservative, uncompromising. To those who would urge her to make her faith easier, more in keeping with the tastes of the changing mentality of the times, she answers with the apostles, we cannot do so.

— Pope Paul VI, General Audience, January 12, 1972

It is sometimes reported that a large number of Catholics today do not adhere to the teaching of the Catholic Church on a number of questions...It has to be noted that there is a tendency on the part of some Catholics to be selective in their adherence to the Church’s moral teaching. It is sometimes claimed that dissent from the Magisterium is totally compatible with being a 'good Catholic,' and poses no obstacle to the reception of the Sacraments. This is a grave error.

— St. John Paul II meeting with U.S. Bishops, Sept 16, 1987

Here we come in contact with the really critical issue of the modern age. The concept of truth has been virtually given up and replaced by the concept of progress. Progress itself 'is' truth. But through this seeming exaltation, progress loses its direction and becomes nullified. For if no direction exists, everything can just as well be regress as progress. 

— From Truth and Conscience, by Cardinal Jospeph Ratzinger

Every believer, therefore, is required to give firm and definitive assent to these truths, based on faith in the Holy Spirit's assistance to the Church's Magisterium, and on the Catholic doctrine of the infallibility of the Magisterium in these matters. Whoever denies these truths would be in a position of rejecting a truth of Catholic doctrine and would therefore no longer be in full communion with the Catholic Church.

— Congregation for the Doctrine of Faith on Professio Fidei, June 29, 1998

"Basing itself on Scripture and Tradition, the Council teaches that the Church, a pilgrim now on earth, is necessary for salvation: the one Christ is the mediator and the way of salvation; he is present to us in his body which is the Church. He himself explicitly asserted the necessity of faith and Baptism, and thereby affirmed at the same time the necessity of the Church which men enter through Baptism as through a door. Hence they could not be saved who, knowing that the Catholic Church was founded as necessary by God through Christ, would refuse either to enter it or to remain in it." Catechism of the Catholic Church [846]