.... worship and manners
Or
..... Worship and proper manners. I guess it's better to translate it into the plural form: "manners," because in general Islam talks about it as a whole entity, which is composed of different conducts/behaviours.

The Definition of MANNERS:

A way of doing something or the way in which a thing is done or happens.A way of acting; bearing or behavior.The socially correct way of acting; etiquette.The prevailing customs, social conduct, and norms of a specific society, period, or group, especially as the subject of a literary work.Practice, style, execution, or method in the arts.a way in which a thing is done or happensa person’s outward bearing or way of behaving toward otherspolite or well-bred social behavior:   didn’t your mother teach you any manners?

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Note added at 14 mins (2021-06-21 18:46:06 GMT)
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https://www.islam.org.hk/ECOI_2012/en/Manner_in_Islam/Manner...

How you behave with others is behaviour.

"Treatment" is the idiomatic expression that means معاملة
According to Oxford Learners Dictionary it is defined as "a way of behaving towards or dealing with a person or thing".

Dealing with Others
Islam/Society and Family/Dealing with Others

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Note added at 4 mins (2021-06-21 18:36:13 GMT)
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"١٣‏/٠٣‏/٢٠٢١ — Islam has established peace as a main principle for Muslims' in dealing with others, Sheikh Ahmed El-Tayyeb, the grand imam of Al-Azhar, said ..."

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Note added at 8 mins (2021-06-21 18:40:37 GMT)
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"Justice in dealing with others is a natural right; it is also the basis for the​ ..."
https://international-review.icrc.org/sites/default/files/ir...
"Islam requires fair behavior in dealing with others, and does not make their ..."
"Tolerance and compassion in dealing with others would have to be important requisites for transaction: “…Let them pardon and forgive. Do you not love that Allah should forgive you? And Allah is Oft-Forgiving, Most Merciful” (24:22)."
https://link.springer.com/article/10.1007/s10943-015-0039-0

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Note added at 1 day 1 hr (2021-06-22 19:53:47 GMT)
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ومعاملة
"and fair behaviour in dealing with others."
"and good manners in dealing with others."

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Note added at 9 days (2021-07-01 14:02:53 GMT)
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Thanks, Daniel, for the observant comment. Your suggestions are definitely good and they convey the meaning, but I thought that “social behavior” is a modern term that is related to sociology, while “معاملة” (معاملة الآخرين) is an archaic religious term. I have also endorsed “Good manners/ Good behavior” and “Manners”. However, I wasn’t aware of the negative connotations in “dealing” that might make me withdraw my answer.