It will come as no surprise to you to learn that, being a very human bunch of people, Spiritualists do not all agree with one another about the various aspects of Spiritualism. It is commonly held that some spirits actively seek communication with the world which they have now left behind.
Mediums only act as channels where a spirit takes the initiative to make contact.
Thereafter, we begin to see differences of opinion. It is also necessary to understand that Spiritualism does not claim exclusivity like, for example, fundamental Christianity. Spiritualism is very happy that many Spiritualists remain attendees at services of orthodox Christian denominations or, indeed, attend Mosques, Hindu Temples or any other place of religious worship. You don't have to attend a Spiritualist meeting to be a Spiritualist. You don't even have to know another Spiritualist in order to be one yourself.