So...why are you insisting Catholics are obedient to "get saved"? How is having the perspective that Jesus opened the way of salvation to all, and people entering the way of salvation (which is obedience to the will of God) any different from your "We are obedient because we are saved--i.e., we are walking in the way of salvation that Jesus opened to all...and that walk following Jesus and the way he opened is obedience to the will of God.
Do you realize you are doing the same thing Catholics do, but have so little love that you try to term what Catholics do in a different way for the sole purpose of vilifying and denigrating them? Where is the love, where is the brotherhood?