I never miss that point; the Lord Jesus Christ is without doubt the good shepherd and the Father without doubt always keeps his promises. That is a given that we both accept in faith.
What I am wondering is how folk like my friend can be so mistaken about their faith and folk like you can be so certain that folk like my friend were never born again. What makes it confusing is that you, for example, assert that you are amongst the saved and that my friend was not even when he was completely certain that he was. Somehow your certainty trumps his, despite your previous indication that you cannot not know what he believes (or believed when he was a professing Christian).
Adding to the wonder is the most recent assertions in your posts that my friend - should he repent and return to the faith - was not born again ... and all of these assertions made with complete certainty in your posts stem from the same texts in the same bible translations that he used when he was an evangelical christian as part of the basis for his own assurance of salvation. He said back then, and I know he said it because I heard his do so, that his assurance rested on the promises of God rather than on his own merits or his own faithfulness. It was, as your posts also imply, all down to God keeping his promises and Christ's work really effectually redeeming the faithful so that their sins - all those in the past, present, and future - are forgiven and totally purged away.