Learn English – the word for a person who does the opposite of what he speaks

A "goody two-shoes" is one possibility. A "saint" is another. A regular [This word makes the appellation ironic] "Mother Teresa". A "fraud" or a "one-dimensional fictional character" [There's nobody who's "never done anything wrong in their life"].

Someone is speaking unintelligibly: being such that understanding or comprehension is difficult or impossible; incomprehensible.

Whether because of mumbling (to speak words indistinctly, as by lowering the voice or partially closing the mouth.), muttering (to speak indistinctly in low tones), garbling (to mix up or distort to such an extent as to make misleading or incomprehensible) or incoherence (expressed in an incomprehensible or confusing way; unclear), it is unclear.

A good thesaurus and these words should get you started on the exact word you want.