What did Jesus say about the seven churches in the book of Revelation?

Revelation 1:11 - "I am the Alpha and the Omega, the First and the Last," and, "What you see, write in a book and send it to the seven churches which are in Asia: to Ephesus, to Smyrna, to Pergamos, to Thyatira, to Sardis, to Philadelphia, and to Laodicea."[NKJV]