I think I would have to technically disagree with this statement. The Catholic Chuch is the one and only true Church founded by Jesus Christ. This is the only place where salvation can be found. Jesus Christ did not found the Jewish or Muslim religions. Granted, Christ was a Jew and they, along with all the other Israelite tribes, were the people of God in the Old Testament. However, the covenant of God went from Abraham, to Moses, to Jesus Christ to the Catholic Church. It is no coincidence that in the Traditional Latin Mass, we speak of Abraham, our patriach, not the patriarch of the Israelites. The Sacrifice and the priesthood were taken away from the Jews and given to the Catholic Church. That is why the Temple in Jerusalem was destroyed. That is why the Jews are no longer able to offer the daily sacrifice. The Mass is now the daily sacrifice on earth, and I believe that if the Sacrifice of the Mass - the re-presentation of the Sacrifice of Jesus Christ - was not offered every day on this earth, our sins would bring the wrath of God down upon this earth and destroy us. Protestant, Jewish, Muslim, Buddhist services - none of these can compare to the importance of the Mass. And therefore none of these religions can compare to the Catholic Church.
The Church teaches that there is no salvation outside the Catholic Church. That does not mean that you must be on a church membership list somewhere to be saved. This, I believe, is where Divine Mercy comes in. St. Faustina tells us that Christ calls out to everyone, constantly extending His Mercy. I believe that He is calling each one of us at every moment in our lives, and that we have a chance at salvation right up to the last moment of our lives. The example of the good thief on the cross tells us that. So no matter what religion you are or no religion, Christ is calling you. Being a good Jew, Muslim, Buddhist means nothing to God. It is the sacrifice of Jesus Christ that will save us, not our good works. So if a non-Christian is saved, it will have nothing to do with their good works. It will be because at some point they accepted the Sacrifice of Jesus Christ, which comes through the Catholic Church. That is why we never judge anyone, not the most heinous sinner. Even someone like Adolph Hitler could have repented at the last moment and been saved. Good works do not save us. Only Jesus Christ saves us.