So what do "once saved always saved" and "by faith alone" actually mean? I heard many protestants trying to explain these but most of the times it was just a very convoluted way of saying "it's faith alone but if you're not a good person then you don't really have faith..." or something in that vein (which is pretty much the same what Catholic and Orthodox churches teach).
Am I saved if I say out loud "Jesus is my Saviour!" but then proceed and commit every possible sin in the book?
14 For sin shall not have dominion over you: for ye are not under the law, but under grace.
15 What then? shall we sin, because we are not under the law, but under grace? God forbid.
16 Know ye not, that to whom ye yield yourselves servants to obey, his servants ye are to whom ye obey; whether of sin unto death, or of obedience unto righteousness?
17 But God be thanked, that ye were the servants of sin, but ye have obeyed from the heart that form of doctrine which was delivered you.
18 Being then made free from sin, ye became the servants of righteousness.
It sais, yes, you were delivered by Jesus but it seems there're some terms and conditions too.
The verses 17-18 are the case in point: if you believe in Jesus from all of your heart, you're the servant of righteousness. Everyone can translate for himself "servant" and "righteousness".
It's still a bit tricky though.
I watched a video of an Russian-German orthodox priest on the differences between Catholisism, Protestantism (in general) and Orthodoxy regarding salvation. He clarified the differences between Sola Fide and the Orthodox position like this:
The catholic/protestan position sees the relationship between God and man as judge and offender. The difference between catholics and protestants is that catholics argue that Jesus saved us not to 100% and we can tip the scales with our deeds. Therefore, for every sin, there is penance. Then Luther came and said that Jesus saved us 100%. It means no penance is due.
So protestantism is like God is a rich dad of a minor who faces serious charges. "Dad" bribes the authorities, so his son's actions have no consequences and he's not compelled to make a U turn to righteousness. If this minor commits another serious crime, the rich dad will bribe the authorities again and again. The minor only has to have faith in the purchasing power of his dad's wallet.
The orthodox position is somewhat different but I think this difference can have tremendous impact on a Christian. Orthodoxy sees the relationship between God and man as father and son. Orthodoxy doesn't deny the fact that Jesus saved us to the degree of 100%. But the believer in Christ is compelled to build a relationship to God. We need to take action and "build back better" (couldn't resist ) what Adam and Eve violated.
Let's say you live with your parents. One day, you take your dad's credit card to subscribe to multiple hoes on OnlyFans. What happens if your father busts you? Call the police (theft is a crime)? Doubt it. Beat the shit out of you? Doubt it. But the relationship to your father as well as trust is damaged. If you have a normal loving family you will naturally seek to win back your father's trust with some deeds. Maybe the father will forgive you anyway, but if you're a good son you'll be naturally driven to make amends.
Maybe this father-son thing is already included in Sola Fide. But you shouldn't invent new fancy terms for what's already in place (and had been for centuries before Luther).