Is that part of myself small compared to that other part of myself? Can you please define what small is, what big is, and can you please explain in what sense do you see the comparison between totally different things?

For example, what can the hand do without the mind? Well, "nothing"! And what can the mind do without the hand? "nothing" at all! You see, all parts of you are important as well.

Your brain contains dozens of functions easy to locate and to define, but if you look closer, then you'll find hundreds of functions, and looking closer, again you'll see more of them, and so on: so it turns out that the more you look close, the more you see all the beauty and the complexity. The brain is billions of billions of neurones, so there's no point in counting the functions, are they are at least as many as the neurones.

Back to your question: you distinguish 1) the body 2) the mind 3) the emotional 4) the spiritual

So, my first questions about that list is:
1) do you really understand all what you quoted? Can you define them precisely? -- I can't
2) can you know for sure if this list of 4 is all that you are? -- I don't think so

Usually, if you want an answer about any subject, you have to find precisely the question, because then, the work for solving is half done