1.
Many sleepless nights allow for questions of why? What am I doing here, and where do I belong? to cloud my mind, demanding answers while none are there.
2.
Therefore, there must be a purpose for each one of our lives, and I want to fulfill mine .
3.
Discovering the reasons for everything while determining my purpose is what matters to me most.
I feel like saying "the reasons for everything" is really broad. And if you do believe in God (as do I) then you would know that while we are living we will never discover the "reasons" or better yet, the answers for the why certain things are the way they are. I would consider re-wording or finding new words for that part.
4.
"how can lack of sun cause depressions? "
5.
Upon mastering great understanding comes the ability to connect with others from multiple different angles.
I don't think this sentence serves any purpose within your essay, and you might want to think about deleting it.
6.
My desire to aid in the struggles that are common to the human race is why my thirst for knowledge is so vital.
7.
Without a strong understanding of the "why's" and "how's" I cannot helpleave behind researchbenefitthat helps to benefit others aslike former erudite scholars have before me.
8. I really like your last few sentences, they definitely add a sophisticated touch to your essay overall. That being said, I see where you're trying to go, but I think with another editing session and some touching up your essay will really shine. Right now it sounds good, but it's not really showing your personality, you know? It is very formal and while I do understand that this is for Stanford and you want to impress (I'm applying there too), you should still keep in mind that your audience wants to know one simple question. What matters to you? They're not looking for a formal thesis, they just want to know what you are passionate about, and I can tell that you do have a yearning for research and studies, but the way you present that in writing almost stifles your voice.
I really hope this helps you out a bit and I wish you the best with all of your applications!! Hopefully we'll both be at Stanford come fall!