One of them consists of commanding what Allah has not commanded, such as associating partners with Him, and forbidding what Allah has not forbidden, such as wholesome things. The former introduces into religion what Allah has not authorized; the latter forbids what Allah has not forbidden.

The same is stated in the authentic hadith narrated by ‘Iyād ibn Himār from the Prophet, peace and blessings be upon him, who related that Allah Most High said:

“I created My servants upright in faith, but the devils led them astray. They forbade them what I had made lawful for them and commanded them to associate with Me partners for which I had sent down no authority.”

For this reason, inventing false forms of worship, such as associating partners with Allah and similar practices, predominates among Christians and those who resemble them among deviant worshippers and Sufis. Inventing unfounded prohibitions predominates among Jews and those who resemble them among deviant students of jurisprudence. Indeed, the foundations of the Jewish religion include burdens and shackles in the form of prohibitions. Hence the Messiah said to them:

“And to make lawful for you some of what was forbidden to you.”

The foundations of the Christian religion include worshipful devotion expressed through ambiguous wording and actions whose significance is not clearly defined. Those whose hearts are inclined to deviate therefore followed what was ambiguous in it, seeking discord and seeking its interpretation.

I have established elsewhere that affirming Allah’s oneness—which means devoting religion sincerely to Him—and the justice we practise together encompass the whole of religion. This comes back to the same principle: devoting religion sincerely to Allah is the foundation of justice, just as associating partners with Allah is a tremendous wrong.