A catholic will argue that they are not yet saved and then point to the passage from the Bible which appears to require perfect behavior to be in the family of God by the presence of God's Spirit in the human spirit.
If the one to whom they aim such a passage (as seen in a recent post to Mark17) makes claim to have been born from above, the catholic mind can reinforce that catholic notion which teaches them they cannot obtain salvation UNTIL they have gone through the hoops of catholic dogma and even a suffering process where they earn entry to Heaven.
If questioned as to their knowing they are saved (not striving to be saved, but saved as in born from above) the catholic can revert to the passage used to try and negate the assurance of salvation the non-Catholic has (as Mark17 has so beautifully shared) and claim that they, the catholics, know they are not yet saved because they are not yet able to behave perfectly before the Lord, as if ANY but Jesus can do that but that they have yet to arrive at such perfects works.
Catholic minds are stuck on a track which reinforces the false notion that in this life salvation rights may be earned, but so few earn them that purgatory must be applied in order to earn the right to salvation.
Of course the Bible not only assures a reader that they may know immediately that their human spirit has been cleansed from unrighteousness and the Holy Spirit of God entered therein, and the Bible even illustrates this TRUTH with two very powerful scenes of the event (the Day of Pentecost following the Ascension and the house of the Roman Centurion, Cornelius). But those illustrations must be explained away because they contradict the magicsteeringthem declarations which catholic minds must follow for righteousness.
It does remind me of circular logic sometimes.
The start of "The Lord's Prayer" teaches us that God is so holy that even His name is holy. That alone gives us much to ponder but one of His names proves the point above "The Lord Our Righteousness". What a awesome name which shows us that our righteousness is not ours and has nothing to do with us. There is nothing left for us to complete when we believe in The Lord.