Revelation 7:13-15

13Then one of the elders asked me, “These in white robes—who are they, and where did they come from?” 14I answered, “Sir, you know.” And he said, “These are they who have come out of the great tribulation; they have washed their robes and made them white in the blood of the Lamb. 15Therefore, “they are before the throne of God and serve him day and night in his temple; and he who sits on the throne will shelter them with his presence.