Are you in a different Church?

Ponder the writing of Saint Thomas Aquinas:

"'One faith,' St. Paul writes (Eph. 4:5). Hold most firmly that our faith is identical with that of the ancients. Deny this, and you dissolve the unity of the Church ... We must hold this for certain, namely: that the faith of the people at the present day is one with the faith of the people in past centuries. Were this not true, then we would be in a different church than they were in and, literally, the Church would not be One." – St. Thomas Aquinas