The foundational belief established through the religion of Submission (Islam) and propagated in God’s final scripture to mankind is that “there is no god beside God.”
3:18 GOD bears witness that there is no god except He, and so do the angels and those who possess knowledge. Truthfully and equitably, He is the absolute god; there is no god but He, the Almighty, Most Wise.
(١٨) شَهِدَ ٱللَّهُ أَنَّهُۥ لَآ إِلَـٰهَ إِلَّا هُوَ وَٱلْمَلَـٰٓئِكَةُ وَأُو۟لُوا۟ ٱلْعِلْمِ قَآئِمًۢا بِٱلْقِسْطِ لَآ إِلَـٰهَ إِلَّا هُوَ ٱلْعَزِيزُ ٱلْحَكِيمُ
47:19 You shall know that: “There is no other god beside GOD,” and ask forgiveness of your sins and the sins of all believing men and women. GOD is fully aware of your decisions and your ultimate destiny.
(١٩) فَٱعْلَمْ أَنَّهُۥ لَآ إِلَـٰهَ إِلَّا ٱللَّهُ وَٱسْتَغْفِرْ لِذَنۢبِكَ وَلِلْمُؤْمِنِينَ وَٱلْمُؤْمِنَـٰتِ وَٱللَّهُ يَعْلَمُ مُتَقَلَّبَكُمْ وَمَثْوَىٰكُمْ
Yet people have set up religious leaders as partners next to god, creating an intermediary between themselves and their Creator.
9:31 They have set up their religious leaders and scholars as lords, instead of GOD. Others deified the Messiah, son of Mary. They were all commanded to worship only one god. There is no god except He. Be He glorified, high above having any partners.