With all those “I want to sell my soul” requests… we should contact eBay and ask them to open a new category for “selling souls” ! If Satan for some reason could be interested in such thing, who knows, maybe other spirits are interested as well. Fair for all 
But since eBay will probably reject the idea because… Demons don’t pay taxes. I suggest you forget about it and learn a ritual to make a pact instead.
Good luck,
Selling your soul is easy. Just tell the devil you want to give him your soul. 
However, you will miss the point of the Creator creating humans after all His creatures.
You are a king, humans are Kings. Fear and false teachings do not want you to know that fact and for you to act on it.
So skip the soul selling part and ask the spirits to do what you want and they will do it without any questions asked.
How I wish we ( humans) know who we are!
You can “sell your soul” as a form of commitment for a pact to show a demon how serious you are and look at it that way, I wouldn’t recommend it because their is a myriad of demons and angels who want to work with you and I lowkey believe committing to one entity is overrated.
In Hollywood contract people have written pact contracts that essentially are written so that whom ever is writing gets to use their power rather than the actual person. So it’s a powerful enhancing spell that opens people up into adept-hood without their knowing. Or so I’ve heard.
I think you are mistaken, my friend. Even if you did ask for something there is a problem, the language you use to speak is in itself a code, a means of communication to filter out what it is you want and dont want in order to communicate: states of being, emotions, feelings, and memories/visions. The likelihood that a new magician would be able to communicate this well enough to get exactly what they want is slim, heck it’s even hard for a more “experienced” magician like myself that’s why we employ the aid of rituals, decoration, sigils, intent, etc etc. It is to further solidify and seedling idea into a full-fledged idea and state of being that matches up well with our will and intentions!
Who’s to say we didn’t come first, and what creator are you referring to GOD, YVWH, Allah, Satan, The Universe, source, ourselves.
Do you see my point here?
This person probably has a very different version of reality than you.
So, belittling their current world view will probably not help as they are NOW just realizing their power or have realized it enough and awoken to the fact they are a living god, now acting upon that new and profound realization to the best of their ability!
Well, I hope you don’t let it hold power over you for too long (if you hate it as much as you say) thoughts and beliefs are possible to change, but you must first be willing to make the necessary changes and plunder into the unfamiliar. For you that sounds like magick, but for others it may be simply be questioning their current faith or practices.
I know exactly what you mean, I thought everyone on here was absolutely nuts for summoning demons, now here i am telling all my friends the second I have an opportunity, blabbering on about the benefits and upsides!
I have to agree with Knight here, it is through humanities perversions that we end up with so many problems when it comes to religions and established ways/teachings of life (like Confucianism).
Have you ever read (one of) The Bible(s)? I mean, in my opinion, it is one of the greatest reflections of reality. Profane, contradictory, and at times a marvel.
It truly is, sighs in admiration one’s hell in a book…
As it looks in the instance and maybe a long involvement that Christian teachings make things so rigid.
However, I believe Christianity have made us enlightened. If you have read the Bible you find some weird spiritual practices esp. the Old Testament. No one will teach that because it is meant for the inquisitive.
Study the Catholic Mass, and what they say, there ceremonial activities and there “Exorcisms”, you will instantly say occult practices. 
Christianity is peaceful, enlightening and a powerful religion where secrets of the occult knowledge are for bythe one who have undying thirst for knowledge or who have a natural affinity to the spirits.
Those who preach against summoning demons say this because of the records and experience on how demons are worshipped which is against the commandments.
As I will always say, we are gods because we are created like God, we are both divine ( celestial ) and human.
I am not stuck within these beliefs and thoughts. But they influence my actions during ritual when I am just starting it for the first time. Like when I did Succupedia’s Letter of intent ritual. I couldn’t meditate afterwards because I was shaking uncontrollably. I would have loved to do the ritual to the T but I couldn’t because the “demon bad, angel good” shit has been in my brain for ages it seems. But with time and confidence I will rid my self of it.
I don’t like Christianity, I used to; but not anymore. I can’t stand it for some reason, I don’t know why.
Do yourself a favor, DO NOT FEEL BAD about a consensual relationship with a lovely soul, I understand new beliefs and faiths can be scary ESPECIALLY when you are threatened by a death from all your previous programming! I can appreciate Christianity though, far from perfect, but it taught me basic human archetypes and a decent moral code (far right and far left aside).
According to the movie Bedazzled it’s $3.47
McDonalds Employee : Hi, how ya doin’. What can I get you?
The Devil : A Big Mac and a large Coke.
McDonalds Employee : It comes to $3.47.
The Devil : [to Elliot] Do you have $3.47? I left my purse in the Underworld.
(From Bedazzled (2000) - Elizabeth Hurley as The Devil - IMDb )