The variety of religious-types who want to push their religions onto others via visits to your home or work; those who call you on the phone, send emails, etc., to try and change your religion to theirs. Or those who want to talk incessantly about their religion to you by calling, emailing, or visiting you without having been invited to do so.
Theisticians can be identified fairly easily. Typically two young men (usually two, sometimes more) nicely dressed in suits and ties - usually on foot - visit your home even though you have a "No Solicitors" sign posted (right by the doorbell, no less). When the sign is brought to their attention, they say, "We're not soliciting, we're not selling anything, we are giving/bringing you the word of God".