Jesus gave a message to the Philadelphia portion of the Church of God in Revelation 3. On December 17, 1983, the late Herbert W. Armstrong gave a sermon titled, "The Mission of the Philadelphia Church Era." In that sermon, he went over the mission of the Philadelphian portion of the Church of God as well as 18 truths he believed that God had him restore that the Sardis era no longer had. In this sermon, Dr. Thiel provides quotes from Herbert Armstrong's sermon, as well as each of the 18 truths. These truths included the true gospel, God's purpose for humanity, the Holy Day plan, governance, what is God, what about man, spirit in man, firstfruits, millennium, truth about the Holy Spirit, begotten now, born-again at the resurrection, identity of physical Israel, Israel in prophecy, multiple tithes, identity of Babylon and her daughters, Satan's deception, and being separate. Dr. Thiel quotes scriptures and/or early church-related writers who understood at least portions of each of those eighteen truths. He also discusses what church teaches these 18 truths and truly carries out the mission of the Philadelphian church era.