Sadly, I must posit again the problem of so many people not believing in hell.
Then, I must list all the way Satan is tricky, very tricky, as he is so much more intelligent than we are. He watches us. He cannot read our minds, but he does watch and wait to trip us up.
Here are some traddie ways to fall into serious sin; this is a special list for my traddie friends and myself.
1. Think you are better than everyone else because you go to the TLM weekly, or belong to the SSPX. This is hubris.
2. Think that Rome is wrong when the Pope makes statements ex cathedra
3. Think that liberal bishops cannot be obeyed.
4. Think that the FSSP is a compromising order (I really do not like this one)
5. Think that Vatican II caused all the problems-you do not know your Church history
6. Think that the Mass and Doctrine were changed in the Vatican II documents-yes, there are vague and confusing statements, but doctrine remains solid.
8. Think that you know better than Rome about issues regarding private revelations.
9. Think that confessions in the SSPX are legal; no, these are not, sadly.
10. Think that you can disagree with the teachings of the Church concerning the Apostolic Succession (sedvacantist position)