This may seem a strangely basic issue to many, as they have this matter entrenched in their mind, but my background makes me unsure of things. I'll briefly elaborate, although at the moment, I'm not thinking as clearly as I otherwise would.
I was not born into a Christian (or any other religious) home and in my teens was a vehement atheist. I was later more questioning and when I was 26, I met people from a religious group called "The Way" (I don't know how many readers have heard of them). They were unitarians (with a small "u" - not the main Unitarian church). At that time, I knew almost nothing about the Bible and precious little about science.
They invited me to attend their meetings, which after a bit I did. I bought some of their literature.
After reading something of theirs, I was stricken with terror. It was about the unforgivable sin. They rendered the matter as follows - paraphrasing:- "He who is born of God has eternal life and the love of God. He who is born of the Devil has eternal death and the hate of the Devil. You cannot repent of seed - it is permanent".
I thought about what I may have done in the past and my former vehemently ungodly attitude.
During the next few months, I frantically interacted with many (nominally) Christian people and denominations, trying to glean knowledge. On the whole to a lesser extent, this attempt at learning and uncertainty has been with me ever since - I'm now 63.
I've "seen" things from both Trinitarian and Unitarian perspectives. I'd say, in the NT, there is, at least on prima facie considerstion, some material that supports either view.
I'd be interested in reading others' (preferably Bible-based) reasoning on this matter.