I think you're confused, Woody.
The result of being sealed (in hell, I presume) doesn't have anything to do with whether or not one hardens one's heart. That's incidental to the fact that he's simply not one of the elect, correct?
For the kingdom of heaven is like unto the bouncer at the door to Studio 54. If you're not on the list, you don't get in. -- Book of Calvin, chapter 7, verse 22.
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No need for a bouncer, those not on the list never get to the door.
If your not on the list, then you will not even show up to check. You have a nasty allergy to music. No bouncer needed!