Revelation 2:10

Revelation 2:10 Do not fear what you are about to suffer. Behold, the devil is about to throw some of you into prison, that you may be tested, and for ten days you will have tribulation. Be faithful unto death, and I will give you the crown of life.

and ye shall have tribulation ten days: meaning it may be the ten persecutions under the Roman emperors; the "first" was under Nero, in the year 64 or 66; the "second" was under Domitian, about the year 93; the "third" was under Trojan, in the year 104; the "fourth" was under Hadrian, in the year 125; the "fifth" was under Marcus Antoninus, in the year 151; the "sixth" was under Septimius Severus, in the year 197; the "seventh" was under Maximinus, in the years 235, 236, 237; the "eighth" was under Decius, in the year 250; the "ninth" was under Valerianus, in the year 257; and the "tenth" was under Dioclesian, in the year 303. Austin (o) reckons the ten persecutions thus: the first by Nero, the second by Domitian, the third by Trojan, the fourth by Antoninus, the fifth by Severus, the sixth by Maximus, the seventh by Decius, the eighth by Valerianus, the ninth by Aurelianus, the tenth by Dioclesian and Maximianus. Others, inasmuch as Nero's persecution was before this vision, reckon the ten persecutions thus: Domitian, Trojan, M. Antoninus, Verus and Lucius, Severus, Maximinus, Decius, Valerianus, Aurelianus, Dioclesianus, Licinius: the Dioclesian persecution lasted ten years almost throughout: and some think that this last persecution, which held ten years, is here particularly meant, and not without some good reason; since it is usual in prophetic writings, and in this book of the Revelation, to put days for years; so that these ten days may be the ten years the last persecution held, and at which time the period of this church state ended, and that of Pergamos took place,

First Christ counsels them not to be afraid of what they are about to suffer. Christ by telling them beforehand is indicating that, as the all-knowing God, it is part of his plan and under his control.

Jesus tells his disciples that in world they will have tribulation, but to take courage; he has overcome the world, cf. 3:21, 5:5. In Luke 12:4 Jesus warns us not to fear man who can kill the body but do no more, we should fear God who, when the body is dead, can cast us into hell. 1 Pet 3:13-18 tells us not to be afraid if we suffer for doing right, we have the example of Jesus who died for doing right but he was raised again (cf. 1 Pet 2:19-25, Isa 51:7-8).