The core sin of Adam and Eve's and Lefebvre's disobedience is the same core of Satan's disobedience: ARROGANCE-PRIDE.
Disobedience began it all. That is how I started off my piece...
...actually, you started off your piece with a gross misstatement of fact, and then proceeded to slime one of the most loyal prelates to the Deposit of Faith ever known, without whom almost the entire Tradition of our Church would exist only in fading memories...what with bishops who hate tradition, caring only for the collection plate, priests not willing to learn a little bit of Latin, and laity looking for the easiest and least challenging liturgy, happily accepting a vapid shell of its former beauty...Lefebvre’s “disobdience” seems more an act of courage, given the hostility to tradition existing in the Church in those days...