Krdytkyu

I grew up in a Muslim-majority country. Do's and don'ts:

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  Do show respect for the religion. That means avoid doing things like comment on how inconvenient it must be to pray five times a day, don't offer non-halal food, don't invite people to lunch during Ramadan, etc.


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  Do do as they do, if possible and not inconvenient. For example if you take lunch together, order/pack something halal. Unless you have special dietary requirements that require you to eat pork, don't eat pork when with others.


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  Do dress conservatively. If your institution has a dress code, follow that. If you're female, you can usually refuse to wear the hijab if it makes you uncomfortable (depends on country however), but still dress conservatively - e.g. don't wear something sleeveless.


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  Don't pretend to be Muslim. You can't fake it. Learning how to pray in the religion takes time; the chant is nontrivial as well.


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  Don't pretend to be Muslim #2: just as important, once you identify as Muslim you could be bound to obey a different set of laws. Sharia criminalizes things which are fine in contemporary Western culture, such as homosexuality. If you're homosexual but identify as Muslim, you could bring the religious police on your head.


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  Don't pretend to be Muslim #3: Further, depending on which country you're in, you could find it really hard to leave the religion. Potential problems you could face go up to death. In the meantime it's not just you that's affected: in many countries, there are restrictions on Muslim persons marrying a non-Muslim; plus any child born to a Muslim is automatically a Muslim.

Exception: if you were originally a Muslim but no longer believe in the religion, you don't have good options. The above advice will still bring the religious police onto you (because you're now an apostate). I would either pretend to be Muslim or leave the country and work elsewhere.

tl; dr: Leave religious people to practice their religion and don't criticize them for it. They should do the same to you.

I also spent a few years in a MENA country in an academic environment. As you say, eating food/drinking water in public during Ramadan was illegal, as were certain standards of dress, however my experience over the years was that this did not in any way mean that the individuals I lived and worked with (including those who were practicing Muslims) were by default unaccepting of my non-religiousness. I am curious why you say

Surely, if they know I'm "non religious" it will annoy them.

and

So even if my supervisor is kind enough as well as his other doctoral student, but they will be disappointed if he know my situation.

Perhaps you have more reason for believing these than you have included in your question, however, in my personal experience, none of my Muslim friends/co-workers ever expected me to conform to their religion. I certainly never pretended to be Muslim, and like other answers, suggest that you do not do this as this is likely to make the situation more awkward ('I converted to fit in' is probably not the best answer to give to an observant member of any religion).

My advice is that perhaps this does not need to a bigger issue than any other lifestyle difference that you might have with your co-workers, and not to read too deeply into it (as in assuming they have some kind of expectation of you), unless they give you reason for it. Government polices do not necessarily reflect individual expectations. By all means, if you feel unhealthy pressure or feel unsafe, don't stay. Otherwise, similar situations where there is a difference in lifestyle/culture between members of the group occur all the time.

Perhaps another group you join might go out regularly for coffee/alcohol when you are unable to join for dietary/religious reasons, or in another group everyone else has kids, so leaves early, or do play-dates on the weekend. But in such situations, the activity you have to miss out on is surely not the only way to build rapport/respect within your group and strengthen your relationship with your supervisor. So if there is no actual pressure for you to have the same religious beliefs, try to decide if you're bothered by their religious belief. If not, then focus your energy on finding some other topic/hobby that you have in common. If both you and they are respectful of differences, there may be no debate to 'open'.

~Note: I am an American, and while I studied at a largely international college with large populations of all major religions, my answer may not accurately reflect cultural expectations in other countries.~

First of all, I do not think that you should pretend to be religious if you are not. It sounds like it would be quite uncomfortable for you, and could lead to many negative feelings if they found out that you had been lying.

Instead, it sounds like you should have a conversation with your professor. It is not reasonable to ask him or other students to refrain from praying. However, it seems like your biggest concern is that it feels awkward and you do not want them to judge you for being non-religious. The easiest way to deal with this is to tell your professor about your concerns and ask honestly if he is bothered by it.

Tell him that you have noticed that he and the other students go pray together and that you have felt uncomfortable by being the only one who does not because you worry that he could be annoyed or feel disrespected by your lack of participation. He will likely say that it does not bother him that you are not religious, although he may be curious as to why you are not if that is the norm.

At the end of the day, if he is uncomfortable having a non-religious student, he may not be a good fit for you. Knowing that will allow you to decide what to do next. It may be possible to change advisors or it may not, but you won't lose anything by having a polite and honest conversation.

I am in the U.S., obviously a very different culture.

The way I think things OUGHT to work is this: If these people you work with have different religious beliefs than you and so periodically go off and pray or do whatever related to their religion, they should not pressure you to participate or penalize you in any way for not participating, and likewise you should not pressure them to not do this. They have the right to practice their religion, and you have the right to practice yours or not practice any.

I don't see why this should be any different than any other difference of interests. Suppose I worked with a group of people who, say, all loved to eat Italian food, and I don't like Italian food, and periodically they all go to lunch together at an Italian restaurant. It would be rude for them to pressure me to eat Italian food just because they like it. But it would be even more rude for me to say they shouldn't eat Italian food because I don't like it, or to complain that I am left out because I don't share their taste in food.

I think you should just accept that you don't share this particular interest with your co-workers and that this inevitably means that you will not share certain activities with them. I'd say, so what?

It depends on which country you are talking about in the middle east. I'm from Iran and I would say not participating in religious practices is really common among young people and if somebody attends those religious practices will be mocked heavily. For the rest of my answer, I assume you are living somewhere maybe in the Arabic countries of the middle east. Also, my answer is not really depends on your relationship with the ones that have strict religious beliefs (it means you can replace your supervisor or his students with anybody else like your friends, family, etc.). Also, I assume you are a Muslim by born (it means you are Muslim cause your mother and father are Muslims) and then you changed your mind based on your personal thoughts.

You mentioned that all of them will pray at the pray time but you don't join them, and some people here suggested that it may implicitly implies that you are not a believer and if they didn't tell you something until now, it's quite OK in their opinion. Unfortunately: It's not true!. It means at the best they just think you may have a good religious reason (e.g. had sex last night and didn't wash your body) and because of that good religious reason you can't join them. Or, for whatever reason you prefer to pray privately.

The main key point is: Did ever your supervisor or his students tell you why you don't participate in their religious practices?

It is a really serious problem if you are Muslim by born and when you grew up you changed your mind to not to be a religious person. In fact, in Islam beliefs, it's not like you can change your mind after sometime and they welcome you and wish you good luck with your personal thoughts and ideas! It could cost you your life (seriously!). But as far as I know, their rule is that if somebody don't believe in Islam or for whatever reason changed his/her mind to not follow Islam's rules, you would be safe as long as you don't express your ideas in any way to the public and your society. This means if your supervisor or his students asked you about why you don't participate in their religious practices? You need to have a really unimportant or common reason for it and not saying I don't believe in your beliefs! I mean you should say I'm a practitioner certainly but for some reason like being sick at the moment, I could not attend those practices with you. Otherwise, if you want to express your true beliefs that you don't believe in Islam, it will lead to a lengthy discussion with them about why you don't do it and they will try to convince you and if you don't accept their ideas it makes the problem bigger and bigger. So, for every time just bring a fake reason and move on, or better idea is: to not to be there when they are practicing their religion. Also, Buffy suggested you to change your location. Honestly, it is not really easy to relocate to somewhere else when you are from middle east and it may be your long-term goal rather than a short-time answer to your question and your situation that you are trying to deal with it.

how do I react to a situation in which they all go to pray except me?
Do you think I have to open this debate with them, and close it once
and for all? Should I to pretend to be like them, pray with them?

It is up to you. If you feel encouraged to accompany them, then you can tell them to inform you, and tell them that you want to accompany them. Otherwise you should not go even if they invite you, you should tell them not to invite you as you do not prefer to.

Religion is something personal. Even in Muslim countries, no one can force you to pray.

In my opinion you should not open debate about this unless if you are interested about knowing more about what they are doing.

Your supervisor has certain rules and regulations to evaluate you. None of them can be praying. Even in the most religious countries. So you should not worry.

An no, you should not pretend to be like them and pray like them. If you do this, you are wasting your time. Your prayers should have meaning to you, and should make you feel better. If this is not the case with you, no one, including God, need it from you.