My point is God hardens men with the Gospel, and then justly condemns them. When God hardens, its judicial and just and its for destruction Joshua 11:20
For it was of the Lord to harden their hearts, that they should come against Israel in battle, that he might destroy them utterly, and that they might have no favour, but that he might destroy them, as the Lord commanded Moses.
Yes the natural man fits himself for destruction because God is fitting him for destruction. All men are born sinners ripe for destruction by nature, even the elect are by nature children of wrath as others Eph 2:3
3 Among whom also we all had our conversation in times past in the lusts of our flesh, fulfilling the desires of the flesh and of the mind; and were by nature the children of wrath, even as others.
So without the intervening Grace of God, the elect also fit themselves for wrath and destruction. God could have hardened them as well if He so pleased and would have been just.
So the non elect natural man cannot but fit himself for destruction since God has already created him for that purpose. Gods Eternal purpose causes our actions.