1 John 3:3, "And every one who thus hopes in him purifies himself as he is pure."
Revelation 7:14 "I said to him, "Sir, you know." And he said to me, "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."
Matthew 5:8 "Blessed are the pure in heart, for they shall see God."