An-Nisa · 4:116

116. Allah does not forgive the crime of associating partners with Him, for anyone who does so and dies in that state will live eternally in the fire of Hell. He may forgive all other sins besides associating partners with Him for whomever He wills if such people die committing those sins without repentance, out of His mercy and grace. Whoever associates anything as a partner with Allah has gone far away from the truth, as he has made the creation equal with the Creator.