Some believe that Machiventa will not come to take personal direction of Urantian affairs until the end of the current dispensation. Others hold that the vicegerent Prince may not come, as such, until Michael sometime returns to Urantia as he promised when still in the flesh. Still others, including this narrator, look for Melchizedek's appearance any day or hour.114:1.4
https://mm.spiritualfamily.net/Urantia_Book-Online_Reader-2019/Paper_114.html#114:1.4