Often many Christians are convinced they know a few Catholics who are saved. Such Catholic individuals seem like good people, they have some familiarity with scripture, and they appear fearful of God.

This however is a very precarious position for one to be in because one that claims to be a Catholic should be aware, at least on a basic level, of what their religion teaches. Consider just a few examples of teachings which Catholics are required to submit to:

-They must merit the graces needed for salvation to attain eternal life (CCC 2010) (Consider Eph 2:8-9)
-They must believe that justification is continually earned and forfeited depending on whether one is in good standing by receiving the sacraments or whether they commit a mortal sin (CCC 1446, 1035) (Consider Rom 4:5,8:30)
-They must believe that the Catholic "Church" is necessary for salvation (CCC 846) (Consider 2 Cor 5:20)
-They must believe that purgatory is necessary to cleanse one's sins that Jesus' blood couldn't (CCC 1030) (Consider1 Jn 1:7)

It should also be noted that even if Catholics don't have clarity on such teachings, because Roman Catholicism has dogmatically declared a false gospel, no Catholic will ever hear the true biblical gospel from official Catholic sources.
One of the best questions we can ask ourselves, Christians who know such "saved Catholics," or the Catholics themselves is, "What is one trusting in to get to Heaven?" How one answers this question will give great clarity on what they really believe. A born again Christian who is saved by Christ will correctly reply that the only thing they had to contribute to their justification was their sin. It is through faith, granted by the grace of God (Eph 2:8), that one turns from what they were trusting in before and believes and is saved by what Christ has perfectly and fully accomplished for them on the cross (Rom 3:22-25).

The mark of a true believer who has been transformed by gospel truth is that they bear good fruit in keeping with repentance (Matt 3:8, 7:17-18; Gal 5:22-23). One can appear religiously moral and seem like spiritual fruit is present but if a basic gospel understanding is not present then one's good deeds are all done in vain (Ps 127:1; Is 64:6).

For the hypothetical "saved Catholic" to exist, one must both believe the biblical gospel of grace and then to be Catholic they must deny that very same gospel of grace. So the reality is that "saved Catholics" are never both saved and Catholic but either saved and not truly Catholic or Catholic and not truly saved. Often times a Catholic will come to saving faith through reading their Bible, attending a Bible study, being witnessed to by a Christian and then linger in a Catholic "church" until they have clarity that they must leave. Such clarity comes from seeing that the Catholic teachings are opposed to biblical truths which have transformed their hearts, opened their eyes, and set them free from the bondage of sin. There should be great concern for the supposed salvation of a Catholic who appears to have embraced the gospel but never finds any reason to come out from Roman Catholic teaching.

Jesus said that no one can serve two masters. Every Catholic when confronted with the biblical gospel must decide if they are going to follow the authority of the Word of God or continue to trust in the traditions of men which have aligned themselves directly opposed to the Word of God.