As we see in the book of Hebrews Christ is NOT reigning over the inhabitants of the earth at present. He is the High Priest (after the order of Melchizedek) in the Heavenly Sanctuary. He is also our divine Advocate and Intercessor (appearing in the presence of God for us).
Now of the things which we have spoken this is the sum: We have such an High Priest, who is set on the right hand of the throne of the Majesty in the heavens; A Minister of the Sanctuary, and of the true Tabernacle, which the Lord pitched, and not man. (Heb 8:1,2)
The book of Hebrews continues to tell us that He will come "a second time". And that is when He will establish His reign on earth.
For Christ is not entered into the holy places made with hands, which are the figures of the true; but into Heaven itself, now to appear in the presence of God for us:.. So Christ was once offered to bear the sins of many; and unto them that look for Him shall He appear the second time without sin unto salvation. (Heb 9:24,28)