Once you've been adopted by the Father, he doesn't disown you. You can choose the gift of chastisement if you are disobedient. But there is no divorce court that you can disown your heavenly father once you have claimed His promise to you.
He who began a good work in you is faithful to complete it.
Ten virgins had oil and their lamps burning. Five made sure they didn’t run out of oil. Five didn’t ‘endure to the end’.
The seven churches in Rev; ALL are told: He that overcometh.
The little word ‘if’ is all over the epistles.
The ‘saved, regardless of faithfulness’ attitude is why divorce is rampant among people claiming Christianity. And most of the mainstream denominations now have nearly empty churches on Sunday morning. At least around these parts.
God is faithful and keeps his promises; man chooses to be faithful, but does reverse his decision and walk away from God. (like Demas)