Duty is to Convey the Message – Not as a Keeper of others faith and morality:

3: 20 but if they turn away – behold, THY DUTY IS NO MORE THAN TO DELIVER THE MESSAGE

Sura-4 [Al Nissa Medina 92]

The Quranic Text & Ali’s version:

مَّنْ يُطِعِ الرَّسُولَ فَقَدْ أَطَاعَ اللّهَ ...  

4:80.  He who obeys the Messenger, obeys Allah:

... وَمَن تَوَلَّى فَمَا أَرْسَلْنَاكَ عَلَيْهِمْ حَفِيظًا ﴿٨٠﴾

but if any turn away, We have not sent thee to watch over their (evil deeds).

C599. The Messenger was sent to preach, guide, instruct, and show the Way, -not to drive people to good. That is not Allah's Plan, which trains the human Will.

The Messenger's duty is therefore to convey the Message of Allah, in all the ways of persuasion that are open to him.

If men perversely disobey that Message, they are not disobeying him but they are disobeying Allah. In the same way those who obey the Message are obeying Allah. They are not obliging the Messenger: they arc merely doing their duty.

May yuti'ir rasu_la fa qad ata_'alla_h(a), wa man tawalla_ fama_ arsalna_ka 'alaihim hafiza_(n).

Asad’s Version:

4: 80

Asad Whoever pays heed unto the Apostle pays heed unto God thereby; and as for those who turn away – We have not sent you to be their keeper.

Pickthall Whoso obeyeth the messenger obeyeth Allah, and whoso turneth away: We have not sent thee as a warder over them.

5: 92 Hence, pay heed unto God, and pay heed unto the Apostle, and be ever on your guard [against evil]; and if you turn away, then know that Our Apostle’s only duty is

a clear delivery of the message [entrusted to him].

6: 104 Means of insight have now come unto you from your Sustainer [through this divine writ]. Whoever, therefore, chooses to see, does so for his own good; and whoever chooses to remain blind, does so to his own hurt. And [say unto the blind of heart]: “I am not your keeper.”