Revelation 3:1-6 "And to the angel of the church in Sardis write,"These things says He who has the seven Spirits of God and the seven stars: "I know your works, that you have a name that you are alive, but you are dead. Be watchful, and strengthen the things which remain, that are ready to die, for I have not found your works perfect before God. Remember therefore how you have received and heard; hold fast and repent. Therefore if you will not watch, I will come upon you as a thief, and you will not know what hour I will come upon you. You have a few names even in Sardis who have not defiled their garments; and they shall walk with Me in white, for they are worthy. He who overcomes shall be clothed in white garments, and I will not blot out his name from the Book of Life; but I will confess his name before My Father and before His angels. "He who has an ear, let him hear what the Spirit says to the churches.'"
Revelation 1:10-11 I was in the Spirit on the Lord's Day, and I heard behind me a loud voice, as of a trumpet, saying, "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."
Revelation 19:8 And to her it was granted to be arrayed in fine linen, clean and bright, for the fine linen is the righteous acts of the saints.
