In a dream it is wealth. Unbelief is also an illness from which its sufferer does not recover and which no medicine benefits. Unbelief is injustice.
Whoever sees that his religion has become corrupt will act foolishly and harm people, just as if he acted foolishly his religion would become corrupt.
Whoever sees that he has gone astray will commit an error, just as if he saw that he erred, he would go far astray.
Whoever sees that his religion has become corrupt in front of a crowd of people will give false testimony before a crowd. It is said that unbelief is denial of the truth; the Exalted said:
قُتِلَ ٱلْإِنسَـٰنُ مَآ أَكْفَرَهُۥ
“Destroyed [i.e., cursed] is man; how disbelieving is he.”
Quran 80:17 · Saheeh International
meaning "how denying he is!" Unbelief is denial of one of the blessings, or of [someone's] companionship. Unbelief may signify the sick recovering after they had come close to death. Unbelief may also signify trial in religion and killing a soul.