St. Paul never said there was salvation outside the Church. As a matter of fact he was martyred for preaching the opposite.
You need to reread the Epistle of the Romans.
Paul says in Romans 2:13-6
“For it is not those who hear the law who are righteous in Gods sight, but it is those who obey the law who will be declared righteous. (Indeed, when Gentiles, who do not have the law, do by nature things required by the law, they are a law for themselves, even though they do not have the law. They show that the requirements of the law are written on their hearts, their consciences also bearing witness, and their thoughts sometimes accusing them and at other times even defending them.) This will take place on the day when God judges peoples secrets through Jesus Christ, as my gospel declares.”