The Archdeacon is coming to evaluate the Anglican church. To avoid the church getting shut down, the Muslims decide to fake being Anglican and come to the service on Sunday. Of course the Archdeacon finds out, but he is in favor of the "interfaith experiment" – as long as it brings in money.
Sarah: Don’t we have a New Testament hanging around somewhere around here?
Yasir: New Testament?
Sarah: Yeah or an Old Testament?
Yasir: If we had a new testament surely I would have thrown the old one.
If this were a Jewish congregation instead of a Muslim one, there are several questions: May a Jew go to an Anglican service? May he pretend to be Christian? And how convincing would he be?
I’m afraid the answer to the first question is most probably no. There are some orthodox Jews who do not enter churches at all, not even for a concert or to admire the art and architecture. Many Jews will in general enter churches, but not attend a Christian service. Some will attend services, for example the (orthodox) then-Chief Rabbi Jonathan Sacks generated some uproar when he attended the wedding service of Prince William in a church. There might be quite a few people who would attend a service for the wedding of a friend or family member, but to attend some regular Sunday service to save the Anglican church? I don’t think so.
As far as pretending to be Christian goes, there might be an issue of "marit ayin", giving a false impression. I’m not entirely sure the concept is applicable here, as usually it is discussed in contexts where something that is technically allowed could give a false impression of what a religious Jew is allowed to do. So for example if a man with a kippah walks into a non-kosher restaurant, an observer could think that it is allowed for religious Jews to eat there. Or if you as a known kosher-keeping Jew serve meat in a sauce that looks like milk. As in the case under discussion there is no "identifyable Jew" involved, I’m not sure marit ayin applies, but I am no rabbi. There might also be other issues with pretending to be a Christian.
Next question, if we assume for dramatical reasons that a Jewish community decides to attend Reverend Magee’s service, would they be able to put on a convincing performance? Well, kippot are easier to hide than headscarves. But (orthodox) Jewish services are much more disorganized and have less of this "awed silence" than Christian ones, I guess there would be more talking among the congregation than the Archdeacon expects. Also singing with an organ, loudly speaking whole prayers in unison and sitting and standing all at the same time will be unfamiliar and could go wrong. I’m not sure if Anglicans kneel, if they do this would present a halachic problem. Also, do Anglicans say the Credo aloud? No Jew would do that, ever (some might maybe sing songs that mention Jesus or Mary, but saying "I believe in Jesus"? No way!).
So, while it would be equally fun to watch a Jewish "Christian" congregation, it would be pretty unrealistic, at least if we take an orthodox community as the example. For a bit of background reading on opinions about Jews in churches you can read Is a Jew permitted to enter a church […]? on JewishValuesOnline.