The man could not number those who are saved

The church of God couldn't be numbered (Revelation 7:9), in contradistinction, to the book of Numbers, where God ordered Moses to number the Israelites, save only the Levites who were meant for the temple. The reason is that the the church of God, the ecclesia, those called out from the beginning, literally those who are of the elect, eternally predestined, chosen in Christ from eternity past are in Christ a royal priesthood, a holy nation who are not prepared for war but prepared for Christ.