I agree with you on the OSAS but my question is on the scripture that states that many will fall away from the faith. What does that exactly mean?
If you’re referring to Matt. 24:10, remember that Jesus was speaking to Jewish men about Israel in the End Times. The context of verse 10 is persecution of the Jews during Daniel’s 70th Week. He’s not talking about the Church, the only group in the history of mankind that’s promised Eternal Security. Besides we’ll be long gone by then.
Both 2 Thes 2;3 and 1 Tim. 4:1 also speak of people falling away or abandoning the faith. But a strong case can be made that a born again Christian no longer has the ability to walk away. 2 Cor. 1:21-22 says it’s God who makes us stand firm in Christ. He anointed us, set His seal of ownership on us and put His Spirit in our heart as a deposit, guaranteeing what is to come. John 10:27-30, Romans 8:38-39, 2 Cor. 1:21-22, 2 Cor. 5:5, Ephesians 1:13-14, and Ephes 4:30 all agree that there is nothing that can take us away from the Lord, not even we ourselves.
Therefore those who “fall away” could not have been truly saved in the first place. They are believers in name only who follow the latest fad and drift away because there’s nothing holding them back. They are not rooted and grounded in faith (Ephes. 3:17-18). Otherwise these verses could not be true.