The dates of their births and deaths of ancient Greek philosophers were always estimated and considered secondary, while their ideas were emphasized. But one of Christianity's major accomplishments was convincing a huge swath of the population that Christ was born in the year 0, and that everything after that counts upward.
Using BC or BCE as a mark of denotation between "then" and "now" seems shockingly religious given its ubiquity in many inquiries into history as well as defining our current year. Yet I see this in articles about history, archaeology, climatology, and so on.
Do academic historians give the alleged year of Christ's birth any credence? If so, how so they justify it?
How does anyone know if Christ was real
The general historical consensus is that there was a historical Jesus who existed, as expanded on by this section of the FAQ. Whether or not this person actually did any of the miracles ascribed to him is beyond the purview of history; that's the bailiwick of the Theology Department over in the building on the far side of the quad.
But one of Christianity's major accomplishments was convincing a huge swath of the population that Christ was born in the year 0, and that everything after that counts upward.
In fact, not quite. Here's the appropriate section of the FAQ, specifically u/sunagainstgold's post as listed and the AskHistorians podcast episode (which is only 23:32 long, so not too chunky). I'll add to those u/J-Force's answer on the chronology of relevant individuals in the Bible.