3:1 Sardis. Sardis, once the capital of ancient Lydia, was a wealthy city about thirty miles southeast of Thyatira.

3:1 name that thou livest. The church at Sardis had many members who were not truly born again, possibly second or third generation “members” who were only nominal Christians, without the zeal or commitment of their forebears who had founded the church. This is typical of many so-called “main-line” denominational churches today.

3:3 as a thief. Every believer, in every age of church history, should be watching for the coming of the Lord (Mark 13:37), for “the day of the Lord so cometh as a thief in the night” (I Thessalonians 5:2; II Peter 3:10). Each of the last four of the seven epistles has a reference to the imminent return of Christ.

3:5 book of life. All whose names are not in the book of life will be cast into the lake of fire (Revelation 20:15), and all who reject the words of Scripture will have their names blotted out (see note on Revelation 22:19). On the other hand, those who overcome will never compromise their faith in Christ, even at the risk of their lives (Revelation 13:8). It seems probable that all who enter the world have their names in the Lamb’s book of life, and are safe in Him until they reach an age of accountability and become conscious sinners. At that point they are spiritually dead and need salvation, but their names are not actually blotted out of the book of life until they have irrevocably rejected Christ.