At the centre of the book of Revelation (more or less) is chapter 11’s vision of two witnesses, which provides us with an important glimpse of churches’ local struggles.
The lives of the two witnesses are closely connected with those of the prophets since the two witnesses are individuals who proclaim the Word of God. Like Jeremiah, they speak words of fire to those who disbelieve them (Jer. 5.14). Like Elijah and Moses, they bring a curse on disobedient nations (Exod. 7.19, I Kgs. 17.1, Jas. 5.17). And, in true prophetic style, they die in Jerusalem (Rev. 11.8, Luke 13.33–34).
At the same time, the two witnesses’ lives are portrayed as a miniature of the wider Church’s life. They’re likened to ‘two olive trees’—namely Zerubbabel the governor and Jeshua the priest (Zech. 3–4)—, in which respect they’re kingly and priestly (though not quite a ‘kingdom of priests’) (Rev. 1.6, 5.10). They’re referred to as ‘lampstands’, which connects them back to the churches in Revelation 2–3 (although there are only two of them rather than seven of them). Just as the beast ‘makes war on and conquers the saints’, so he conquers and kills the two witnesses (11.7, 13.7). And, just as the Church at large is vindicated at the end of a three-and-a-half-year period of time (20.1ff.), so the two witnesses are (visibly) raised to life at the end of three-and-a-half units of time (though the units are days not years), which turns the beast’s apparent victory into defeat (11.9–13).
As such, the two witnesses’ lives are a microcosm of the book of Revelation as a whole. History is fractal, and so Revelation is fractal. What’s played out on the stage of world history is also played out on smaller scales. Jesus warned one church that he’d come and snuff them out (2.5), another that he’d come and fight against the Nicolaitans in their midst (2.16), a third that he’d visit them like a thief in the night (3.3), etc. These warnings don’t envisage a global ‘day of the LORD’. They refer to particular points in time when Jesus comes and settles account with individual churches (Mal. 3.18).
Revelation 11 is similar in that it depicts local rather than global events. At certain points in their lives, many churches will look like they’ve been overcome by the world/beast (or simply run out of steam), yet these churches will suddenly receive new life—life that will serve as the sign of Jonah to those around them (11.13).
Viewed as such, the vision of Revelation 11 is an important picture of churches’ individual struggles, framed within the Church’s overall story.

James, what do you believe / know about the Nicolaitans?