"Strange how each religion or grouping of similar faiths has its distinctive jargon and identifying marks."
Differences in beliefs will create different jargon to state their differing ideas. Even if two groups are identical to each other they may evolve different phrases for the same thing due to their isolation from each other. That would be equivalent to genetic drift where one species develops different genes from her sister species in another continent.
As you Co co are well aware, language is fluid and changes within time and region. Example, British and American English.