He has ordained for you of religion what He enjoined upon Noah and that which We have revealed to you, [O Muḥammad], and what We enjoined upon Abraham and Moses and Jesus - to establish the religion and not be divided therein. Difficult for those who associate others with Allāh is that to which you invite them. Allāh chooses for Himself whom He wills and guides to Himself whoever turns back [to Him].
He has ordained for you religious matters similar to what I instructed Noah to convey and act on and what I have revealed to you, O Messenger. He has ordained for you similar to what I instructed Abraham, Moses and Jesus to convey and act on. The gist of this is: Uphold the religion and leave out division therein. What you call the idolaters towards, such as the declaring the oneness of Allah and leaving out the worship of others besides Him, is difficult for them. Allah chooses whichever of His servants He wills and guides them to His worship and obedience and He guides to Him those of them who return to Him by repenting from their sins.