When capitalized, the ‘c’ in Catholic Church indicates a proper noun, meaning the organization whose leader is the Pope. When not capitalized, it indicates the universal church. At the time of Council, there was only the Catholic Church, however, the Armenians, Copts, and Greeks were not unified with Rome, which was one of the reasons for having the Council.
Secondarily, to use the quotation to justify the requirement all Christians be Roman Catholic, is out of context.
While I believe the fullness of the Christian truth is found in the Roman Catholic Church, and would hope all come to Jesus through it, it isn’t up to me.
God is a just and merciful God. He alone determines entrance into Heaven.
How is it out of context? This quote is still true and accurate.