John of Patmos is the name given, in the Book of Revelation

Book of Revelation

The Book of Revelation is the final book of the New Testament. The title came into usage from the first word of the book in Koine Greek: apokalupsis, meaning "unveiling" or "revelation"...

, as the author of the apocalyptic text that is traditionally cannonized in the New Testament

New Testament

The New Testament is the second major division of the Christian biblical canon, the first such division being the much longer Old Testament....

. According to the text of Revelation, John is living on the Greek island of Patmos

Patmos

Patmos is a small Greek island in the Aegean Sea. One of the northernmost islands of the Dodecanese complex, it has a population of 2,984 and an area of . The highest point is Profitis Ilias, 269 meters above sea level. The Municipality of Patmos, which includes the offshore islands of Arkoi ,...

, where by some, he is considered to be in exile.

In Christian denominations, John of Patmos is regarded as a prophet

Prophet

In religion, a prophet, from the Greek word προφήτης profitis meaning "foreteller", is an individual who is claimed to have been contacted by the supernatural or the divine, and serves as an intermediary with humanity, delivering this newfound knowledge from the supernatural entity to other people...

 and a saint

Saint

A saint is a holy person. In various religions, saints are people who are believed to have exceptional holiness.In Christian usage, "saint" refers to any believer who is "in Christ", and in whom Christ dwells, whether in heaven or in earth...

 who receives divine revelation. He has been referred to as John the Divine, John the Revelator, John the Theologian, Eagle of Patmos and John the Seer.
According to the text in Revelation, John of Patmos is instructed to write to the Seven Churches of Asia

Seven churches of Asia

The Seven Churches of Revelation, also known as The Seven Churches of the Apocalypse and The Seven Churches of Asia , are seven major churches of Early Christianity, as mentioned in the New Testament Book of Revelation and written to by Ignatius of Antioch...

.