NOTES for Rev 3:1-6
Jesus gives His apostle no details about the situation in the church of Sardis, perhaps because they were already well known to him. We, of course, are in a different position today, and we can only guess at the details of the problems in the church of Sardis. Judging by the Savior's words in verse 3, one can say that this church was in a state of spiritual laxity, so that Jesus had to remind the Christians of Sardis of what He had often told His disciples during His earthly ministry: spiritual sobriety and readiness to meet the day of Judgment, which can come unexpectedly.
Of course, this does not at all mean that all the Christians of Sardis knew how serious the situation was. Unfortunately, as long as everything in the church outwardly goes on as before and its members preserve the appearance of ordinary Christian life, only someone who himself lives a normal spiritual life can recognize the spiritual problems that have arisen in the community.
Meanwhile, when events develop unfavorably, fewer and fewer such people remain in it. A closed circle arises, and the only way out of it is direct intervention from above, when God allows something to happen that can at least disturb the community's outward well-being and force its members to think about what is going on. Of course, such a shock by itself does not guarantee the right conclusions, but it does give the church community a chance to rethink its own life, repent, and turn to the One who, if asked, will help deal with any problem.
Still, in the church of Sardis, as we can see, there did remain a certain number of those who lived a normal spiritual life and had to understand what was happening in their community (v. 4). As we can see, they could not change anything, because no one else besides them was interested in it: the majority of the church members were satisfied with the state of affairs that Jesus condemned so severely. But even though they were unable to do anything for their own church, these people preserved the main thing: that life of the Kingdom which they had received by following the One who brought the Kingdom into the world (vv. 5-6).