12, 13. (a) What purifying has been necessary for the anointed priestly class? (b) How do the great crowd also benefit by cleansing?

¹² A purifying work was needed. It is described at Malachi 3:1-

Prophetically, Jehovah had asked: “Who will be putting up with the day of [the messenger’s] coming, and who will be the one standing when he appears? For he will be like the fire of a refiner and like the lye of laundrymen.

¹³ That anointed priestly group numbers only 144,000. (Revelation 7:4-8; 14:1, 3) What, though, of other dedicated Christians today? Now increasing into the millions, these form “a great crowd” that also has to be cleansed of worldly ways, ‘washing their robes and making them white in the blood of the Lamb.’ (Revelation 7:9, 14) Thus, by exercising faith in the ransom sacrifice of the Lamb, Christ Jesus, they are able to maintain a clean standing before Jehovah. They are promised survival through the entire great tribulation, the fear-inspiring day of Jehovah.​—Zephaniah 2:2, 3.