Question: "What is the Vatican / Vatican City?"
Answer: The word “Vatican” is from the Latin vaticanus which means “hill.” The Vatican is the palace in Vatican City that is used as the official residence of the pope and the administrative center of the papacy. The term "Vatican" also refers to the authority and jurisdiction of the pope.
The Vatican is a government unto itself. It appoints its own ambassadors and receives ambassadors from other countries. It has a papal archive, a library, a museum, and a publishing house. The Vatican is a small city/state. It is a self-contained city with everything it needs to survive as an independent state. It is recognized by world powers and most nations have ambassadors to the Vatican.
The Vatican is also known as the Holy See, defined as the jurisdiction of the Vatican under the authority of its Bishop known as the Pope. The “See” is the central government of the Roman Catholic Church. The Holy See has its own diplomatic corps and appoints ambassadors to other nations. From a diplomatic standpoint, the Holy See acts and speaks for the Roman Catholic Church. Other sovereign nations recognize the Holy See also as a sovereign nation and appoint diplomats and ambassadors accordingly.
The establishment and management of foreign relations are solely under the authority of the Pope through the Secretariat of State. Both the Holy See, the sovereign body of the Catholic Church, and the Vatican city/state have always received full recognition of their particular international natures. They are members of international organizations; they take part in international conferences and adhere to international agreements.
The Vatican was founded following the signing of the Lateran Pacts between the Holy See and Italy on February 11, 1929. These were ratified on June 7, 1929. Its nature as a sovereign state, distinct from the Holy See, is universally recognized under international law. The Vatican is an absolute monarchy with the Pope at its head. The pope holds all legislative, executive and judicial powers. The Pope is elected by the College of Cardinals. During the time between the death of a Pope and the election of a new Pope, the powers of government are exercised by the College of Cardinals.
The judicial bodies of the Vatican are made up of a judge, a tribunal, an appeals court, and a Supreme Court. All of these bodies were enacted by legislation in November, 1987. These bodies serve and exercise their authority in the name of the Pope. The Vatican also has specific penal and civil codes in force within the government. In conclusion, the Vatican is not just a center of religion, but a center of government for that religion.
The Bible nowhere supports the idea of the Christian church being its own sovereign nation. Jesus made it clear that His kingdom is not of this world (John 8:23; 18:26). The Bible never condones or encourages the establishment of earthly kingdoms or diplomatic entities because these things, by their very nature, focus attention on the world, which is passing away (1 Corinthians 7:31; 1 John 2:17). Christians are to be focused on the heavenly kingdom and our only diplomatic efforts are to be spreading the gospel of Jesus Christ and warning others of the wrath to come.