Still, New Jerusalem is clearly described in Revelation. What they were talking about is this. When a person repents and accepts Jesus as their savior, they are no longer under the rule of Satan, but have come under the rule (kingdom) of God. Their is always spiritual action before physical action. Jesus is the first fruits, He is in a resurrected body, He did not leave His body here. Paul said we look through a glass dimly, we do not what we shall be, but we shall be like Him. Jesus is described as having feet like brass, hair like wool and Eyes of fire.
I don't know about you, but when I got saved, mt body did not change. My spirit changed and my mind is being renewed by the word. But, know physical change. I am still in this sinful flesh body.
Why did Jesus say when you see these things come to pass look up for your redemption draweth nigh. Were we not redeemed at salvation? what was He talking about?
Jesus will return with all the saints and destroy the Antichrist (Not Satan) and defeat the his armies at Armageddon and then rule from Jerusalem for 1,000 years. This is not the last battle. It is not the end of the world. It is the beginning.