[Elsie]

You just don't get to declare yourself a good Catholic simultaneously.

Spoken like a 'True Scotsman'!

[Wyrd bið ful aræd]

Not at all. The Church has set rules which it lays out right off the bat. If you wish to be a member, you assent to the rules. Simple.

A better example of the True Scotsman fallacy would be "all saved people are good. If you're not good, then you weren't saved after all."