In Revelation 3:1-6 .
The message to Sardis  
3 To the angel of the church in Sardis write: He who has the seven spirits of God and the seven stars , says this: I know thy works , that thou hast a name that thou livest, and art dead . 2 Be watchful , and strengthen the things that are ready to die: for I have not found thy works perfect before God.3 Remember therefore how thou hast received and heard, and hold fast, and repent. Well if you will not watch, I will come like a thief, and thou shalt not know what hour I will come upon ti.4 Thou hast a few names even in Sardis which have not defiled their garments, and they shall walk with me in white , because they are dignas.5 who overcomes shall be clothed in white garments, and I will not blot out his name from the book of life , I will confess his name before my Father, and before his ángels.6 who has an ear , let him hear what the Spirit says to the churches .

The city of Sardis  was the capital of the ancient kingdom of Lydia and undoubtedly , in his time, was an important city . It was located roughly 80 miles of Ephesus and her five major roads converged , so that Sardis was an important trade center . It also had its military significance because it was located on top of a hill , which made it almost impassable . Spiritually , Sardis was saturated with the cult of pagan goddess Artemis. Moreover, this city was known for its textile industry. There fine cotton fabrics were manufactured . But at the time John wrote Revelation, Sardis had lost much of the splendor it enjoyed in the past. We would say it was a city that only thing left is the name . A city living in the shadow of the glory.
Sardis was a church works , but with little life. Once had a reputation of being alive , but now even Faith was dead.
Jesus warns the saints ( 1) Be vigilant, be alert , (2 ) affirm the little they have , (3 ) recall the word that they have received and heard, (4 ) preserve and prepare for when He comes .
Verse 5 Amucha bothered people, because it seems to suggest that the names of the unfaithful Christians will be erased from the book of life. The book of life contains the names of all who are born . The names of those who reject Jesus Christ are erased from the book because they are dead .
The sender is presented as one who has the seven spirits of God . Seven is the number of perfection and what is complete. With this, Jesus is showing that nothing escapes his questioning look. Jesus Christ knows the actions and attitudes that cause those actions. Furthermore, Jesus Christ, the sender of the message is presented as having the seven stars . This means that Jesus has control of the churches and their leaders , because the seven stars represent the leaders or spokespersons in these seven churches.
We found the evaluation of the reality of the church of Sardis, intimately connected with the claim that Jesus makes this church . Unfortunately , something like what happened to the city of Sardis was going on with the church of Sardis . It was a church living under the shadow of the glory.
Revelation 3:1 in the second part says: ” I know thy works , that thou hast a name that thou livest, and art dead ”
He who knows absolutely everything that hath the seven Spirits of God and the seven stars , has detected the deplorable condition of the church of Sardis . His verdict is clear: you have a name that you live , but are dead. For all practical purposes , the church in Sardis was nothing more than a neat mausoleum. It looked attractive on the outside , but inside was full of corpses. Speaking of bodies , I mean people who had fallen asleep on the laurels of past victories . Sure, they thought everything was fine. They had a beautiful temple , lavish buildings, enjoying fellowship , attendance was very good , finances were at their peak , but in reality , it was all artificial. Things were done out of habit. It was just a mechanical exercise of singing, praying , collect the offering , hear the message and go until Sunday to repeat the process , and so Sunday after Sunday .

Jesus therefore said to them : Have name that thou livest and art dead . Many churches today are like the church in Sardis , right? A church and Jesus Christ makes a recommendation .

Jesus says to this church and all who are like her: Be watchful or awake. Do not go more like you’re dead asleep . Then, once you wake up , strengthen the things , perhaps few , still living , but also die soon if you do something about it. Immediately after , remember what you have received and heard , save it and repent. This means , again do what you did in the past, to not only live the glories of past victories .
What recommendation as precise and clear. If you notice that your church is a well maintained , etc. , it is time to wake up and not continue to act as dead, because you have the name of one who lives . Begin to cultivate the things that have not yet been extinguished in his spiritual life . Perhaps prayer or reading and studying the word of God or Christian service. Anything that is still on but with a flame and shuts down. Start with something. Stoke that fire and that will lead you to revive other things I used to do before, but inexplicably have become extinct in your life. If the church in Sardis was ignoring the recommendation of Jesus Christ , we expected a severe judgment from Jesus Christ . In her dream come Jesus Christ as a thief in the night , that is, at the least expected to give their due to this church’s name lives but in practice it is dead now. Amid the recommendation , Jesus refers to a small group of believers in the church in Sardis , who refused to be carried away by the stream of mortality prevailing in the church.
They Revelation 3:4 where it says relates : ” 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 ” Thank God throughout the existence of the church There has always been a small remnant that has remained true to the principles of the word of God. In the darkest night , a few stars will always shine . They are not allowed to take his clothes pervasive smell of death that pervaded the church in Sardis . These people will be awarded , walking with Christ in white . Denoting intimate communion with the Savior in an atmosphere where sin has no involvement .
The reward in Revelation 3:5-6 says: “He who overcomes shall be clothed in white garments, and I will not blot out his name from the book of life , 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 ”

The winners are the true believers. His works are the result of their genuine faith. To them Jesus promises the following : To be clothed in white garments . This denotes a righteous life before God. Then , their names will not be blotted out of the book of life . This indicates security salvation. Nothing can make a true believer to lose his salvation . Finally , confess your name before the Father and the angels . This is a kind of celestial appreciation for the loyalty of the victors.