[Subfallen]

I think there is some ambiguity in your question...the psychology of theism spans an enormous spectrum. (And some theisms I personally wouldn't want to psychologize, even if I could.) Anyways, I can't answer your question, but can point out a distinction.

It is this: even theists vary wildy in their willingness to ascribe spirituality to their experiences.

Some theists are happy to see God's hand in everything. These credulous people believe that the enjoyment of a religious social gathering is Divine fellowship; and that the peace they feel when reading Scripture is direct proof of a personal relationship with Jesus.

Other theists are sufficiently self-skeptical that they have had only a few experiences where they felt genuine spiritual authenticity. (Actually, I suspect that many, many theists have never had an experience to which they could ascribe spiritual authenticity---if they were being completely honest.)

My point is just that the psychology behind proselytizing depends heavily on where a theist falls on this continuum. And certainly other variables are at play as well.