polytheism
Also verse 2: 163 emphasizes the unity of God
The testimony of the unity of God and the consequent rejection of idolatry is the most important article of faith of Islam. Polytheism is absolutely contrary to the strict monotheistic teachings of Islam, that polytheism is the greatest sin. [52] The Qur'an According to the worship of other gods besides Allah, the only sin is forgiven under any circumstances.
"God does not forgive adjacent to it (in any gods). What's under (d. H. Less serious sins) that forgives whom (is given) wants. And if one (the one) God (other gods) contiguous, which is (therefore the right path) astray. "