Christianity When Christianity began, it was one religion with one denomination. Now it has grown into one of the main world religions with many different denominations. Over the years, as one church split from another and opposition became common, the beliefs began to change, though the core has still remained. Fifteen of the most common Christian denominations follow, with their similarities and differences exposed. In all Christian churches certain rituals are present. However, what they are called and how many are recognized tends to vary. Both ROMAN and ORTHODOX CATHOLICS recognize seven sacraments. EPISCO