The word tribulation has become so uncommon in the English language that it conjures up the idea of a grandiose event or some far out future time that has little to do with today. Yet for John, it is a normal word that means signals a fiery trial or suffering—something that he and the seven churches that he addresses must prepare for.
While more could be said here, since the Book of Revelation speaks of all sorts of fiery trials or events, it is worth pausing to see how John (and Jesus) speak of tribulation in Revelations 1–3 to get a sense of what the word means. (I will leave the question of tribulational timing for another time.)
John himself claims to partner with the seven churches in the kingdom, tribulation and endurance (Rev 1:9). He specifies that he shares in these because he is “in Christ” just as they presumably are (1:9). The particular tribulation that John cites is his exile to Patmos due to his testimony to Jesus (1:9). He must then endure this tribulation.
The churches’s tribulation
As a partner in tribulation, John expects the audience of his epistle, the seven churches, to also experience tribulation and thus endure it for the reward set before them. For example, Jesus says of the church in Smyrna:
“I know your tribulation and your poverty (but you are rich) and the slander of those who say that they are Jews and are not, but are a synagogue of Satan. 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.” (Rev 2:9–10 ESV)
They are in tribulation, and they will have ten days of tribulation—even up to the point of death. Concerning the church in Thyatira, Jesus says, “Behold, I will throw her onto a sickbed, and those who commit adultery with her I will throw into great tribulation, unless they repent of her works” (2:22 ESV). Thyatira must then continue to endure as it has in the past (2:19).
Other churches endure or must endure as well which implies the presence of tribulation (Ephesus in 2:2, 3; Philadelphia in 2:10). Pergamum has even experienced tribulation to the point of death, as Antipas died for his testimony of Christ (2:13).
Partners in tribulation
This explains why John can assert, “I John, your brother and sharer in the tribulation, kingdom, and endurance in Jesus …” (Rev 1:9). His tribulation is exile in which he endures by testifying to Christ. And by being in Christ, John knows himself to be a shared in the tribulation and endurance of the seven churches as well as a shared in the kingdom because they are all in Christ (1:9; cf. 1:5, 6).
Whatever else tribulation means in Revelation 1–3, it certainly relates to the present trials, need for endurance, and kingdom that all Christians together share in. The suffering of one Christian is the suffering of another because all are in Christ.