Actually trad123 it's better to use encyclicals against the VII Popes, as you have been doing, things like Lumen Gentium and "Muslims worship the one true God," because people can say that what JPII did at Assisi was not binding, was just a personal fault. They might refer you to Alexander VI having orgies and so on.
But Assisi TOGETHER with the heresies and errors in encyclicals tells the whole sordid story. The problem for you is that most of the heresies of VII are the same heresies you hear among trads, that you can be saved in false religions. If you are unaware of this heresy, or don't believe it is heresy, you will be more likely to get sucked in to either VII or SSPX, as a form of mild resistance.
But no Pope ever taught salvation in false religions before Pius XII, they expressly condemned it ( actually he didn't teach it through his own mouth, he just supposedly approved of Suprema Saec Hacra ) so once again we have two Magisterii in contradistinction to each other. So if you're going to believe Pius XII is a true Pope, you will have to buy his innovation on EENS and on NFP. I do not. What I call the "liberal sedes" have.