[RegulatorCountry]

The Roman Catholic Church has a seat in the United Nations. Ergo, the Roman Catholic Church is a State. It's a State that, as you helpfully note, issues its own postage stamps, currency, has its own diplomatic corps and laws. The Roman Catholic Church is the original State Church and remains so.

[Mrs. Don-o]

"The Roman Catholic Church has a seat in the United Nations."

This is factually incorrect. The Stato della Città del Vaticano has a seat at the United Nations.

The Catholic Church per se, has existed since Pentecost. Vatican City as presently constituted as a City-State was established by the Lateran Treaty in 1929.

When Vatican City ceases to exist (I suppose when the Muslim Cultural Enrichers lob a nuke at it, probably called "Abd Allah" or "Shaitan") the Catholic Church will still exist. And through eternity.