Well, Paul's letters for the Body of Christ from Romans to Philemon is about OSAS, for example Romans 5:12-19.
Think of it this way, when you were in the first Adam, was that anything you can do, other than turning to Christ, that can make you lose your sinful nature?
If you want to take a passage that mention not inheriting the kingdom of God, which has nothing to do with salvation, to overturn the rest of what he taught us, that is a choice you are making.