Apocalypse Revealed # 608
608. Let him who has understanding calculate the number of the beast. This symbolically means that one who is enlightened by the Lord can discern the character of the arguments the clergy use from the Word in defense of that doctrine and faith.
"Let him who has understanding" means, symbolically, to be in a state of enlightenment from the Lord. To calculate the number means, symbolically, to discern the character - a number symbolizing character (nos. 348, 364, 448), and to calculate meaning, symbolically, to discern. Moreover, because the character symbolized by the number is the character in respect to truth, and all truth having to do with the doctrine and faith of the church is founded on the Word, therefore the character meant is the character of the arguments the clergy use from the Word in defense of that doctrine and faith. This also is the character symbolized by the number 666, which we consider below.