Kur’an 4:48 — sura An-Nisa, 48. ajet

إِنَّ ٱللَّهَ لَا يَغۡفِرُ أَن يُشۡرَكَ بِهِۦ وَيَغۡفِرُ مَا دُونَ ذَٰلِكَ لِمَن يَشَآءُۚ وَمَن يُشۡرِكۡ بِٱللَّهِ فَقَدِ ٱفۡتَرَىٰٓ إِثۡمًا عَظِيمًا

Allah neće oprostiti da Mu se neko drugi smatra ravnim, a oprostiće manje grijehove od toga kome On hoće. A onaj ko drugog smatra Allahu ravnim čini, izmišljajući laž, grijeh veliki.

Indeed, Allah does not forgive association with Him, but He forgives what is less than that for whom He wills. And he who associates others with Allah has certainly fabricated a tremendous sin