The Light - 24:31
And tell the believing women that they should guard their eyes and guard their chastity and not show their fair parts except those which should be uncovered. Let them cover their veils over their breasts. And let them not show the fair parts of their bodies to anyone except their husbands, their fathers, their husbands´ fathers, their husbands´ fathers, their sons, their husbands´ sons, their brothers, their brothers´ sons, their sisters´ sons, other women, male servants and laborers who do not have sexual power, and children who do not yet understand the sexual aspects of women. And let them not stamp their feet to show off their hidden parts. O you who believe, turn to Allah collectively so that you may be successful.
The most important criterion of belief:
The Cattle/6:82
Those who believe and do not mix their faith with wrongdoing, they deserve security and they have found the truth.
Luqman/31:13
"When Lokman advised his son, he said: "My dear son, do not associate partners with Allah; surely shirk (associating partners with God) is a great wrong."
The Companies/39:65
It has been revealed to you and those before you that if you associate partners, all that you do will be in vain and you will be of the losers.