I'm saying, contrary to what you have said, that if you believe the SSPX is teaching heretically, it is your duty to avoid them even before the Church makes any decisions about it. It does not matter whether the error is in good faith or not! This topic is NOT complex Arvi.
Today, that is a good formula only for not going to mass anywhere, being a home aloner.
All the sede groups and SSPX seminaries teach that Jews, Mohamedans, Hindus, Bhuddists..... can be saved by their belief in a God that rewards.
Clear dogma says that one can't be saved even if they shed their blood for Christ, but the sede & SSPX priests teach or are taught that anyone can be saved just by believing in a God that rewards. Go figure!
Pope Eugene IV, Council of Florence, “Cantate Domino,” 1441, ex cathedra:
“The Holy Roman Church firmly believes, professes and preaches
that all those who are outside the Catholic Church,
not only pagans but also Jews or heretics and schismatics, cannot share in eternal life and will go into the everlasting fire ..and that
nobody can be saved, … even if he has shed blood in the name of Christ[/b], unless he has persevered in the bosom and unity of the Catholic Church.”
Pope Innocent III, Fourth Lateran Council, Constitution 1, 1215, ex cathedra: “There is indeed one universal Church of the faithful, outside of which
nobody at all is saved, …
Pope Boniface VIII, Unam Sanctam, Nov. 18, 1302, ex cathedra:
“… this Church outside of which there is no salvation
nor remission of sin… Furthermore, …
every human creature that they by absolute necessity for salvation are entirely subject to the Roman Pontiff.”
Pope Clement V, Council of Vienne, Decree # 30, 1311-1312, ex cathedra:
“… one universal Church, outside of which there is no salvation, for all of whom there is one Lord, one faith, and one baptism…”
Pope Eugene IV, Council of Florence, Sess. 8, Nov. 22, 1439, ex cathedra:
“Whoever wishes to be saved, needs above all
to hold the Catholic faith; unless each one preserves this whole and inviolate, he will
without a doubt perish in eternity.”
Pope Leo X, Fifth Lateran Council, Session 11, Dec. 19, 1516, ex cathedra:
“For, regulars and seculars, prelates and subjects, exempt and non-exempt, belong to the one universal Church, outside of which
no one at all is saved, and they all have one Lord and one faith.”
Pope Pius IV, Council of Trent, Iniunctum nobis, Nov. 13, 1565, ex cathedra: “This true
Catholic faith, outside of which
no one can be saved… I now profess and truly hold…”
Pope Benedict XIV, Nuper ad nos, March 16, 1743, Profession of Faith: “This faith of the Catholic Church, without which
no one can be saved, and which of my own accord I now profess and truly hold…”
Pope Pius IX, Vatican Council I, Session 2, Profession of Faith, 1870, ex cathedra: “This true Catholic faith, outside of which
none can be saved, which I now freely profess and truly hold…”