If you’re genuinely saved, then you will persevere in faith and good works. And the reason we persevere is that God preserves us. As Philippians 2 says, we “work out our salvation” because God works in us—the willing and the working.
Beware of Apostasy
I’ve heard it said “once saved, always saved.” It’s true, but I think it’s misleading. It’s misleading because it may imply that once you’re saved, it doesn’t matter how you live, that you’re “in” no matter what. But that’s not how the Bible speaks.
The Bible repeatedly warns us that God will not finally save you if you don’t persevere in the faith and good works. So not everyone who claims to follow Christ actually follows Christ. What seems to be genuine faith may actually be spurious. And that’s why the Bible repeatedly warns those who claim to be Christians to beware apostasy.
Here are three examples. Romans 8:13 says, “For if you live according to the flesh you will die, but if by the Spirit you put to death the deeds of the body, you will live.” So if you characteristically live according to your sinful nature, you’ll experience eternal death.