Ok I'll break down for you breh breh cause I wuv u
The devil is not a person or thing it's the physical/material world.
So the only way to really sell your soul to the devil is to gain a lust and obsession for the material world.
Think of it as like the anti secret or some shyt.
You become what you think about.
If you believe in god you should walk in his image.
If you believe in material gain and riches walk in that image.
Become what you seek.
How would a person of wealth that sold their soul for riches would act? Dress? Talk? Think?
Just be warned you will pay the consequences
