I would venture to say all religions have formal rituals. That is part of what gives a religion its identity. Rituals evolve and become obsolete as most religions mature. It is these rituals that often relect the times in which they are practiced. Some religions may be more ritualistic than others but it would be hard to find one with no known rituals. In many cases what one person would call a "ritual" another would call a "sacrament" or even "common practice." A movement may start as a Philosophy, but when rituals are added, it became a religion. Example is Buddhism.