[Safrguns]

But Christ doesn't arrive until AFTER the witnesses have been killed, which is AFTER the anti-christ has power, because the witnesses are denouncing the anti-chrsit.

You are referring to Christ's arrival at the end of the tribulation and at the beginning of the millenial reign.
The rapture does not entail christ's arrival, but rather the Holy Spirit's departure (with Christ's bride)

[concretebob]

and nowhere does it say anyone is going to be exempt from the tribulation.

[concretebob]

How can one depart, when one hasn't arrived?

He is only coming back one more time.

This time, to kick butt and take names, literally.