The Book of Revelation 1 - The Seven Churches

The book of Revelation describes a series of visions that the apostle John had on an island called Patmos.
The seven churches mentioned are: Ephesus, Smyrna, Pergamum, Thyatira, Sardis, Philadelphia and Laodicea. In these letters, John warns each of the churches about their strengths and weaknesses, and instructs them to correct problem areas in their faith and practice.
He also speaks of the dangers of Apostasy and the need to persevere in the Faith.
The letters to the churches are not limited to the problems of the first century churches, but are also applicable to the churches of today.