Revelation 3:3

Remember therefore how thou hast received and didst hear; and keep it, and repent.

Earle, in this and the preceding verse, found five steps to a revival: (1) "Be watchful"; (2) "Strengthen the things which remain"; (3) "Remember"; (4) "Hold fast"; and (5) "Repent."[12]

Remember ... "Memory is again the lever for repentance, as in Revelation 2:5"[13] See notes on that verse, above. And just what were those things they were supposed to remember? We are not told, but Hinds is probably correct in the view that:

This could include the miraculous proof which may have been present when the church was established, a remarkable evidence of the truth of the gospel; but it may have reference to the sincerity and enthusiasm with which they accepted the gospel.[14]

[12] Ralph Earle, Beacon Bible Commentary, Vol. 10 (Kansas City: Beacon Hill Press, 1967), p. 515.

[13] James Moffatt, Expositor's Greek New Testament, Vol. V (Grand Rapids, Michigan: Wm. B. Eerdmans Publishing Company, 1967), p. 364.

[14] John T. Hinds, op. cit., p. 54.

If therefore thou shalt not watch, I will come as a thief, and thou shalt not know what hour I will come upon thee.

It is common for interpreters to make this mean that John is warning Sardis to be prepared for the Second Advent; but as Caird noted, "If we allow John to speak for himself, he is clearly saying that the coming itself is contingent on the church's refusal to repent."[15] Thus, as in the other references to "the coming" in these chapters, it is a "coming in judgment" that is meant, not the final Advent, but a providential visitation upon the sinful. The Second Advent is not contingent upon any group's repentance. When our Saviour gave the great Olivet discourse (Matthew 24; Mark 13; Luke 21), he mingled the prophecies of the destruction of Jerusalem and those of the Second Coming, some of his discourse referring to both events, the first as typical of the second; and the same method is here employed. Therefore, the warnings of providential judgments and "trials" coming upon the church, with the admonitions to "watch," etc., likewise have their application to the ultimate Coming of the Son of God in glory.