Romans 1:28 isn't talking about saved people who became lost by failing to keep themselves saved.
It is speaking of those that had the knowledge of God... so it couldn't be talking about sinners who had never been born again since they've never had the knowledge of God.
Surely you aren't suggesting that Christians can reject God and still be saved are ya?
That's in opposition to God's Word and is what the heretic Gnarly Charlies Stanley teaches!
In his book, Eternal Security, Stanley says
"Even if a believer for all practical purposes becomes an unbeliever, his salvation is not in jeopardy” (Chapter 10, p. 93)
“Christ will not deny an unbelieving Christian his or her salvation because to do so would be to deny Himself” (p. 94).
“Believers who lose or abandon their faith will retain their salvation, for God remains faithful” (p. 94)
He actually taught one can be a "gay christian" and still go to Heaven proving he is a false teacher!
Here's a video where you can see video of Charlies saying this (just a few minutes into the video)
In this video, Gnarly Charlie says he's proud of Andy and supports him after heresy charges
Can a Person Live a Life of Sin and Remain Saved?