The Revelation 7:13-15

Then one of the elders answered, saying to me, “Who are these dressed in white robes, and where have they come from?” I said to him, “Sir, you know.” Then he said to me, “These are the ones coming out of the great tribulation. They have washed their robes and made them white in the blood of the Lamb. For this reason, they are before the throne of God, and they serve Him day and night in His Temple. The One seated on the throne will shelter them.