The Bible indicates that all of us who are true believers today will reign with Christ during the thousand year reign from Jerusalem. We will either be resurrected or raptured, and will exist in glorified bodies (Revelation 20:4-6). The text says that “they will be priests of God and of Christ and will reign with him for a thousand years.”
This passage indicates that we have two roles. One, as rulers will will help with the administration of justice. Also as priests (all true believers are priests already), we may have a role in leading worship. But in addition to this we will probably have a teaching role. There will be many generations of humans born in those days that have never known hunger, disease, war, or political injustice. They will no doubt take many of their blessings for granted. Those of us who have lived in the “Old Earth” will be able to tell them about the kinds of disasters that used to plague the planet on a regular basis. We will tell them how blessed they are to not live in it, and remind them of the need to repent of their sins.