However, you are correct that a whole lot of people don't even follow the doctrine that they (officially) profess. Actually, it begins before that ... they don't even know the doctrine that they officially profess ... see your data about only 48% of Catholics believing Jesus lived without sin.
Catholic catechesis has stunk in this country since the early 1960's. And, unfortunately, we aren't the only ones who can make that claim.
I would wager that a far larger number of those Catholics know that the Church teaches that Jesus lived without sin and yet they don't believe it. In the same way that the Proddies know that their churches teach that avenging oneself is wrong but they do something different. So, doctrine is not the biggest problem there in my estimation.
I disagree. Wrong doctrine is a big problem.
There's error. Which is abundant. And damnable error. Which is not nearly as abundant, at least in my estimation.
I would qualify that with my own quote.
The internet has done for heresy what the printing press did for Protestantism.
-the808bass