More as a parable metaphor vision...as symbol it was meant to convey meaning and understanding comfort and warning...
These souls that were under the altar actually parrot what those living wish to know..."when comes vengeance?"
so immediately anyone reading these revelations will be comforted to know they were given white robes and told to keep resting a little while longer...so I see it as they were already resting...sleep? Sure...physical body dies turns to dust otherwise known as sleep and the soul dies and sleeps but some rest in heaven...especially those killed for Him...and the spirit returns to its creator...
The dead know nothing...but here in this vision at the time of the fifth seal...this symbolism provides a real hope and comfort...namely that death by persecution for His Name's sake will last only a little while longer...keep resting...(it echoes the prayer that the living may also still rest (keep Sabbaths) during times of trouble...)
If taken too literally this vision is not a comfort...do the souls say anything else? See? feel? Are they aware?
Their plea for vengeance and retribution sounds more like something from hell...not those at peace and security in paradise...and they were not answered but left in suspense...
What is that number to be completed? 20? Million?
Are they going to witness its fulfillment? See their friends and loved ones tortured and finally killed?
Much was revealed to John as symbolic...
But as He said of His friend Lazarus...He sleeps...He is dead...that was real...not a parable
Being dead is nothing...let the dead bury themselves...Follow Him...to life...