The early Christians soon became known as Catholic...by the first century...Christ did not use the word Catholic but He did order his followers.to go forth and teach ALL NATIONS (universal)...The reason that it is the true religion is that He started it, it grew from His mission on Earth and it was the ONLY CHRISTIAN RELIGION for 16 centuries. The wannabees came along and decided that they could change the rules as they saw fit.
Documentation?
etymology of ‘catholic’
catholic (adj.)
“of the doctrines of the ancient Church,” literally “universally accepted,”
from French catholique,
from Church Latin catholicus “universal, general,”
from Greek katholikos, from phrase kath’ holou “on the whole, in general,” from kata “about” + genitive of holos “whole” (see safe (adj.)).
Since much of the early writings of the apostles were put into greek, the term ‘catholic’ was used as the adjective to describe Christians as a whole.