Do you mean Jesus is reigning right now? Because even though He might be reigning in our hearts, he is not exercising power over the nations of this world. If all the nations were his right now, He would be doing a horrible job. If you haven't noticed, the world is a horrible place. In the future, my friend, he will reign Luke 1:32,33 and Rev 19,20. But not right now.
This is what happens when you try and fit Revelations into the past. IT IS FUTURE!