The Quran

وَاتَّبَعتُ مِلَّةَ آبائي إِبراهيمَ وَإِسحاقَ وَيَعقوبَ ۚ ما كانَ لَنا أَن نُشرِكَ بِاللَّهِ مِن شَيءٍ ۚ ذٰلِكَ مِن فَضلِ اللَّهِ عَلَينا وَعَلَى النّاسِ وَلٰكِنَّ أَكثَرَ النّاسِ لا يَشكُرونَ

Muhammad Asad

and I follow the creed of my forefathers Abraham, Isaac and Jacob. It is not conceivable that we should [be allowed to] ascribe divinity to aught beside God: this is [an outcome] of God's bounty unto us and unto all mankind¹ - but most people are ungrateful.

Since God is almighty and self-sufficient, it is not for His sake that man is warned not to ascribe divine qualities to aught beside Him: the absolute condemnation of this sin is solely designed to benefit man by freeing him from all superstition, and thus enhancing his dignity as a conscious, rational being.