It is, but he or she said "mostly" because of the catholic church and that might be true, because they are the oldest and still most powerful single organization of the abrahamic religions.
What's an older and more powerful single institution of an abrahamic religion? I can only guess you are referring to something involving Judaism but there is nothing even remotely like the Catholic church (large, rich, organized, formal creed, central authority, standardized practice across large territories) in thousands of years of the history of Judaism.