What Does White Mean In The Bible

White symbolizes purity in the Bible as it is worn by Saints killed during the great tribulation. Jesus is also believed to return a second time riding a white horse with angels dressed in white.

"I 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" - Revelation 7:13-14

"I saw heaven standing open, and there before me was a white horse, whose rider is called Faithful and True. With justice, he judges and wages war. His eyes are like blazing fire, and on his head are many crowns. He has a name written on him that no one knows but him. He is dressed in a robe dipped in blood, and his name is the Word of God. The armies of heaven were following him, riding on white horses and dressed in fine linen, white and clean." - Revelation 19: 11-14