The Bible says that we deceive ourselves if we say we have no sin, the difference is that anyone who is born again doesnt live a life that is dictated or defined by sin.
1John 3:9 Whosoever is born of God doth not commit sin;
for his seed remaineth in him: and he cannot sin, because he is born of God.
I trust the KJV above all other Bibles, but still like to use various others for enhanced understanding of certain scriptures, namely the amplified bible.
1 John 3:9 Amplified Bible (AMP)
9 No one who is born of God [deliberately, knowingly, and habitually] practices sin, because [
a]God’s seed [His principle of life, the essence of His righteous character] remains [permanently] in him [who is born again—who is reborn from above—spiritually transformed, renewed, and set apart for His purpose];
and he [who is born again] cannot habitually [live a life characterized by] sin, because he is born of God and longs to please Him.
If someone is in Christ they are by biblical definition a
saint and no longer a
sinner by label. They sin, but their life is no longer dictated or governed by the power of sin, neither does God impute their sin unto them or hold their sin against them in judgment, because of Christs work.
I believe Catholics for the most parent arent saved just like I believe most church going people who profess to be Christian are not saved. I will say that anyone can get saved as a catholic, or even a newly saved person may attend catholic church, but they wont remain there, because I believe God would lead them out by the leading of his spirit. Jesus said he would give his people the spirit of truth that would lead them into all truth. God is sovereign and active in the lives of his people, he does have ways of speaking to their heart and revealing things to them such as the deception of the catholic church.
In regards to your question about OSAS, I believe so scripturally from what I had pointed out earlier, but like any doctrine there will be those at variance.