**It is indeed a gift; but any gift can be rejected.**
Exactly. The five foolish virgins didn’t take additional vessels of oil to refill their lamps, like the five wise did. They had no more to add when their lamps were ‘gone out’ (Matt. 25:8).
Of the seed that the sower sowed, there was some that sprouted (except the seed die, it cannot give new life. Born again.), that didn’t have staying power (persecution and tribulation that offends. Cares of this world, deceitfulness of riches that choke the word).
That tells me that one can be born again, and lose out; not because of God, but because of the free will of man to turn his back on God, what ever the reason.
Paul said that “Demas hath forsaken me, having loved this present world,..”. 2Tim. 4:10
I don’t believe that Demas was never born again, for Paul was so gifted that I’m sure that he would have discerned if he had been faking his rebirth.
How does one unseal what God has sealed with the Holy Spirit?
A lot of Christians have been taught that BACKSLIDING is PROOF that the person was never born again to begin with.
This is a result of thinking (Being taught) that one can NOT loss their salvation by ANY means.