To be more precise, what matters is not so much what God/gods "think", but what they want us to do. In this case, the textual foundation for Extra Ecclesiam nulla salus
is Mark 16:16: "Whoever believes and is baptized will be saved; whoever does not believe will be condemned." Assuming these really are the words of Jesus, they leave very little for interpretation, no matter what Vaticanum II says.
Only if your priest disallows other interpretations. Here people can disagree what constitutes faith. Many Christians believe that God is everything good, so if you share good values, it's thinkable you are effectively a decent Christian. But yeah, for Protestants faith is formality: if you only believe in these and these letters and remain a miserable sinner, you get a ticket to heaven.
These can not be the words of Jesus since the language of these words did not exist at the time (assuming a deity that doesn't express itself in yet unformed languages).
