According to Osho, this “religion” is the first and the last because it is not a creed but silence itself—the wordless realization that comes before all doctrines and completes them. After awakening, questions fall away and a single, nonverbal answer remains. Silence is both the origin prior to concepts and the final fulfillment beyond them—hence first and last.
It’s called the first and last because it starts before words and ends after all questions—in a silence that answers everything.