Wow, that sounds like a really interesting story! I love writing that explores the concept of Satan. In college, I majored in Religion, so these sorts of concepts are within my interest and expertise. I find the nature of evil, Satan, and magic fascinating and have quite a bit of knowledge in that area.
I would be a great candidate for this job. I have been doing some ghost writing jobs for fantasy books and have had positive feedback. With the clients I've had, some of them have expected me to able to pick up from where they left off and figure out a way to move the plot along, so I am confident that I could do the same for you with the chapter that you are stuck on.
I would, of course, love to read the first chapter and whatever you have in mind about the second so that I have context and can produce the result that would go along with your writing and hopefully give you some inspiration to continue.
I hope to hear back from you. I would love some more details about the book.