>The only religious organizations that go door-to-door are Mormons and Jehovah's Witnesses.
Those are not the only religious door knockers.
Mormons will be two males in dark suits. Regardless of where they are from, their clothing comes from Mormon Casting, branches of which are found through out the world.
JWs will be two women, or a man and a woman, or a man and two women. (A team is training might consist of two men, or two men and one woman.) Their attire is appropriate for a professional office.
The Scientology advocate will be one person, of either gender, in attire that might be appropriate for casual Friday at the office. (On second thoughts, HR will probably write them up for failing to adhere to the casual Friday dress code.)
2x2's will be either one man and one woman, or two men, in attire that is appropriate for a professional office.
Groups of more than three are either leafleting or pamphleteering the area, and not knocking on doors. Typically they have no idea what to do, if you open the door when they put their material on your door.
The other religious groups that go door knocking are extremely rare, and have no consistent patterns.
Amber