At the time, my belief, is that all the major religions were the truth for their age but they were mostly shunned and persecuted minorities when they appeared just like Jesus and Noah.
Then gradually they all became majorities in their regions of the world. From only a handful, Hinduism, Buddhism, Christianity, Islam, Judaism, and the Zoroastrian Faith came flourishing civilisations and learning. An ebb and flow.
They arose from a minority, then reached their golden age as a majority, then declined and another religion dawned. We’ve witnessed the rise and fall of all these kingdoms, civilisations and religions over time. None remain intact. but all came from minorities and won hearts and minds to become majorities.
I don’t believe that numbers is at all relevant to truth because all the major religions were once only a handful of followers that centuries later budded into great civilisations and centres of learning.
Truth, I believe, is determined instead, by the Word of God, not the clergy or what the minister says. So I accept the Words of Moses, Buddha, Krishna, Christ and Muhammad’s as infallible truth, but not what theologians or preachers say, because I believe they are imperfect and make mistakes.