Hi Hutch, I hold to once saved, always saved. Nothing a person can do after salvation will lose his or her salvation. And yes, I agree that those who claimed to believe, then renounced their faith were never actually saved, God never credited their faith as righteousness and transferred them into Christ.
Recall 1 Peter 1:3-5. Once you are saved, God has caused you to be born anew, He protects your future inheritance by His power. Again, my understanding of scripture is that a person can put their faith in Christ and not be "automatically" saved. For example Soil #2 of Matthew 13 put his faith in the gospel, but was not saved. He fell way because he lacked a deep root (deep commitment) to serve Christ no matter the earthly cost.
Election for Salvation is described in 2 Thessalonians 2:13. God chooses individuals for salvation through (1) sanctification by the Spirit and (2) faith in the truth. Thus no individual was chosen for salvation before they had "faith in the truth." Next, only God determines if a person's professed faith is actual living faith and not dead faith. Thus only if God credits a person's faith as righteousness, does God then set the person apart, transferring them from being "in Adam" (the realm of darkness) and into being "in Christ." So I am saying an individual person becomes "elect" or chosen when God credits their faith as righteousness, not when they profess faith in Christ.
Divine Knowledge in another topic that I suspect we hold differing views. But lets stick to discussing our differences on being chosen for salvation.