We have to understand dispensational salvation in order to not mix the application of different salvations that are intended for different ages. Whenever the Bible talks about salvation to do with works, the context will always refer to Jews (in the Old Testament and Tribulation). However, the church age (i.e. Pauline Epistles) is a no-works period.
The Apostle Paul was ministering to the Gentiles, not to the Jews. That’s why none of Paul’s epistles point towards salvation by works.
Catholics (and other cults) will use the following verse to say that we need to have works accompany salvation.
Philippians 2:12 Wherefore, my beloved, as ye have always obeyed, not as in my presence only, but now much more in my absence, work out your own salvation with fear and trembling.
It did not say work for your salvation. It said, work out your salvation. That means you’re not working to get saved. Salvation was already in you before you worked. Basically, this verse is saying that we shouldn’t waste the salvation that was given to us by Jesus Christ; why not put it to good use now (by going to church, praying, reading the Bible, etc.)? This is shown in the following verse.
Philippians 2:13 For it is God which worketh in you both to will and to do of his good pleasure.
How can you work out your salvation if you didn’t have salvation to begin with? Philippians 2:12 is a verse that applies only to saved Christians. If unsaved people do works, it counts for nothing.
The following Ephesians epistle is interesting because Paul is talking about salvation through faith in verses 8 and 9 but in verse 10, this “work” is referring to the Christian walk. We are exhorted to walk with God and produce good works; being in Christ enables us to do good works.
Ephesians 2: 8-10 For by grace are ye saved through faith; and that not of yourselves: it is the gift of God: Not of works, lest any man should boast. For we are his workmanship, created in Christ Jesus unto good works, which God hath before ordained that we should walk in them.
There’s another verse that explains how God comes into us. The holy spirit comes into us and seals us. We are sealed all the way until the end. Isn’t it a waste that God is inside you and that we do not do anything good with it? That’s the meaning of working out your salvation. God is in you, so work out this salvation. We are sealed all the way until the end, you can’t lose your salvation. You can’t even work until you get saved. That’s why we have the saying that the Holy Spirit fills so much in you that it can even come out of you and affect people around you.
Ephesians 1: 13-14 In whom ye also trusted, after that ye heard the word of truth, the gospel of your salvation: in whom also after that ye believed, ye were sealed with that holy Spirit of promise,Which is the earnest of our inheritance until the redemption of the purchased possession, unto the praise of his glory.