Claim: Tonga is a Christian country.

A Christian state is a country that recognizes a form of Christianity as its official religion and often has a state church , which is a Christian denomination that supports the government and is supported by the government . Historically , the nations of Armenia , Aksum , Georgia , as well as the Roman Empire and Byzantine Empire declared themselves as Christian states . Today , several nations officially identify themselves as Christian states and/or have state churches , including Costa Rica , Denmark , England , Greece , Iceland , Liechtenstein , Monaco , Tonga , Tuvalu , Vatican City , and Zambia . A Christian state stands in contrast to a secular state , an atheist state , or another religious state , such as a Jewish state , or an Islamic state .