In theory, one can believe and despair or even believe and actually hate God. On the other hand, a living faith issues forth in repentance and in attempts to make restitution, insofar as we can, and to do better whenever we find that we have sinned--which is pretty often.
I think that we are pretty much agreed on all these points. Then again, as I said above, those are and have been the Catholic views on these matters all along. For this reason, at the level of doctrine or dogma, Luther's and Calvin's revolution was for naught.