Verses with the word sardis in the New Testament (3 verses):

Revelation 1:11
Saying, I am Alpha and Omega, the first and the last: and, What thou seest, write in a book, and send it unto the seven churches which are in Asia; unto Ephesus, and unto Smyrna, and unto Pergamos, and unto Thyatira, and unto Sardis, and unto Philadelphia, and unto Laodicea.

Revelation 3:1
And unto the angel of the church in Sardis write; These things saith he that hath the seven Spirits of God, and the seven stars; I know thy works, that thou hast a name that thou livest, and art dead.

Revelation 3:4
Thou hast a few names even in Sardis which have not defiled their garments; and they shall walk with me in white: for they are worthy.