AND I SAW
John is just doing what he was told to do (Revelation 1:11). At the end of chapter 19 and the first three verses of chapter 20, we see how evil (or demonic activity) will be inhibited from functioning on this earth. The devil is thrown into the abyss with no way to escape until after the thousand years are over. The beast and false prophet are already consigned to their eternal prison, the lake of fire.
We could think that there then is an absence of governance, assuming that governance during the tribulation is totally evil. However, as this verse starts out, there will be governance (THRONES) and the rule of law (judgment was given to them). Many expositors try to explain who the "they" are who are sitting on the THRONES. The most acceptable answer would be the joint heirs with Jesus Christ (Romans 8:12-17 and Galatians 4:1-7) and/or the 'bride of Christ' (Revelation 19:8). The vanquished evil is replaced with the "good" and is typified by the white robes, the righteous acts of the saints. It is not for us to determine who they are; Christ has already done that (Revelation 19:9).
These people have a special place in the heavenly kingdom (Revelation 6:9-11). They were/are 100% totally committed to Jesus Christ even to death. Oh, that we may learn from their example!
and they came to LIFE and REIGNED WITH CHRIST for a THOUSAND YEARS.
The promise to the "overcomers" at Smyrna (Revelation 2:10) is finally fulfilled.
When we consider that the SOUL most likely is a thought (neural) process, that is, a decision consciously made in our minds. Then the SOULS, that were severed from the body (BEHEADED) are reunited with the BODY, where LIFE is. You may have a different view of where the SOUL of a person is, but that explanation needs to fit within the context of this verse. Most interesting to this author is that John SAW the SOULS. That means SOULS have form and are visible. We truly have a lot to learn about the spiritual/soul side of man.
An aside: much can be said about the relationships between body parts and sensory receptors (neurons?). Many times in scripture the sensory physical is refered to as "the heart". Mount Sinai Medical literature indicates that DNA within the zygote encodes both the bodily and the sensory functions.
What is not described is how neural processes control belief, impressions, and intentions (soul or spiritual functions). We all answer at some time during our physical life: 1. Who am I? 2. Why am I here? and 3. Where am I going (eternally)? See Romans 8:26-39 and Hebrews 4).