points to cover:

How God uses symbols - Zion, The kingdom of heaven

How God looks at the Timing of His work
- Counts from beginning
Rom. 4:17(F108)
Zech. 4:10
Isa. 34:2

How to understand Revelation - Rev. 1:1

"God is his own interpreter and He will make it plain"

Plagues

Rev. 15:1 - Great and Marvellous
15:2-4 Song - 1st words - Great and Marvellous

15:5-8

Why not more plainly stated?

Timing

Rev. 6:9-11
Rev. 16:1-2

Dan. 5:25-28,30
Rev. 16:12

Rev. 16:17-21