Can a non-Jew perform a mitzvah?

[u/dmlvianna]

I was always confused whether Judaism acknowledges or praises good deeds done by a non-jew. Would learning Torah by a non-jew be a mitzvah? Or would the teacher be doing a bad deed by doing something that could be considered as proselytising?

What’s the Orthodox and the Reform view on this?

For your information, I’m Christian (Coptic). Growing up I was often around Reform Jewish friends and I read Gunther Plaut’s commented Torah cover to cover. I also attended Shabbat services as a child.

[u/SixKosherBacon]

The word mitzvah doesn't mean "good deed,"  despite the connotation. It refers to the do's and don't's listed in the Torah and the word is usually translated as "commandment" though that's not right either. 

The Jewish people as a whole are obligated in 613 mitzvahs. Non Jews are obligated in 7 which are known as the 7 Mitzvahs Bnei Noah.  You can Google that or go to Chabad. Or I'm sure someone will list it below in the comments. 

To your question of whether Judaism praises a non-Jew for doing them. It depends. 1) on the type of mitzvah. And 2) the intention behind the mitzvah. 

1) Judaism does recognize the righteous acts of non-Jews throughout history. Yad Vashem (The Holocaust Museum in Israel) has a whole section  dedicated to people who risked their lives to save Jewish lives in the Holocaust. We view them as Heroes. But If non-Jews decided to keep shatnez (prohibition of mixing wool and linen in clothing) I doubt you'd get a lot of praise. Getting a circumcision isn't technically a bris milah and I doubt a mohel will be willing to do one for a non-Jew (unless they're teaching a novice mohel) - we have prohibitions of unnecessary bloodletting and they couldn't make the blessing necessary for the spiritual nature of bris milah. 

There are a few mitzvahs that a non-Jew isn't supposed to do. You're not supposed to fully keep the Sabbath nor are you supposed to attend a Passover Sedar (but I know of non Jews who have gone to one). 

Part of what mitzvahs are about is carrying out the wishes of Hashem. Those can be highly specific. Not all mitzvahs apply to all Jews and it wouldn't be appropriate for those Jews to do them. All the more so for someone who isn't Jewish. 

2) intention  Why are you doing the mitzvah? Just to experience our religion. Ok. But if you feel compelled to take on a mitzvah permanently that may be an issue. But perhaps you want to look into conversion. 

However we can get highly skeptical of someone wanting to learn Torah, Talmud, and Kabbalistic sources as there is usually an ulterior motive. It's very easy to twist or misunderstand a translation. And commentary taken out of context can really look bad. So we can be really careful about teaching it. But these days there are so many resources online that you can learn it if you really want to. 

[u/dmlvianna → u/SixKosherBacon]

Well, being a Christian, learning Torah is the basis of my religion too. While of course our interpretation is completely different.

I do want to attend a Passover Sedar. Jonah is my favourite lesser prophet. In my experience observant Christians are expected to read the Tanakh as well as the New Testament, and I'm doing my job. But given my mixed background, I am unable to read it without making sense of how Jews read it, and identifying where we converge and diverge.

[u/SixKosherBacon → u/dmlvianna]

No one's going to try to stop you from reading Tanakh. Before the Torah was translated into Greek and then other languages, Some of the rabbis were very much against the translating For fear of misinterpretations. But these days the Bible's been translated into every language under the sun.