For a start you may want to reduce your use of capitals, writing in all caps is very much frowned upon by moderators.
Also the fact that you are Christian makes no difference, some people (myself included) don't even believe in a soul, or any reasoning behind why someone would want to buy one off you.
The fae tend to be a tricky bunch, some are very friendly, some are less so, just like people. It is good to make positive connections with the fae and particular individuals before you consider summoning one, as much like people many won't want to be disturbed by a random stranger.
Try putting out honey, or sugar water for them, leave small offerings and start to build connections before you summon, you may find that some like to hang around and take part in rituals, while others may not, it is very unclear whether the fae even work with energies like we do, so whether one can be your magickal partner or not is unknown, maybe someone with more fae experience can answer that portion of your question.