Council - 42:22
You will see the wrongdoers in anxiety as their deeds come upon them. Those who believe and do righteous deeds are in the gardens of the heavens. They will receive whatever they wish in the Presence of their Lord. This is a great bounty.
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.