You skip the 5 first chapters, but they show one thing, from the end of the letters to the seven churches, you won't cross the word church anymore, something has changed, the following chapters relates the fate of christians who thought were saved, with the jews and the rest of the godless people.

They will witness the wrath of the Lamb AND, PLUS, the wrath of the father, gradually with mercyful advice before each woes are executed (still room for repenters), that's key to understand, once the church is snatch up by the Lamb(jesus), the shock of the revelation will suck many too hardcore repentance, that's where, in time, the son of perdition should be revealed and go against that wave of revival of a 'new born' church, that means a lot of sufferings, torture ect...at that time some will learn that the flesh doesn't save when you're tortured beyond expectation to rebuke the Savior, others will joyfully step to the guillotine to deliver their spirits.

Didn't summarize the first 5 chapters because they
introduce John and the importance of the 7 churches
of Asia minor receiving this message.

It is dictated to him by Jesus.

Many say the reason why the churches aren't mentioned
after chapter 5, is the church is raptured.

I'm not sure I agree with that assessment.

But would like to talk about the various churches
that existed at the time, and in many cases symbolize
the churches of today.

One easily recognized is the laodicean church - where
Jesus states it is neither hot or cold and he
could spew it out of his mouth. Pretty strong
words.