'Purify' in the Bible

Some of those who are [spiritually] wise and have insight will fall [as martyrs] in order to refine, to purge and to make those among God’s people pure, until the end time; because it is yet to come at the time appointed [by God].

Many will be purged, purified (made white) and refined, but the wicked will behave wickedly. None of the wicked shall understand, but those who are [spiritually] wise will understand.