what is the purpose of your life?

Do you have any idea as to why you are living in this World? You need to have "to" in this sentence.

I need a solid reply please.

There is an English proverb and it says "By service we keep faith".  I'm not sure exactly what it means because it is a bit ambiguous. I also do not know where it came from or who wrote it.

For me, this proverb means that even though I am not always sure what my purpose is in life, by helping/serving other people I can see a little bit of something bigger than me (Like God or Spirit).  If I dont help other people then I don't always feel that I am connected to anyone or anything.  This is why I am a Teacher, I really love helping people in any way I can. Teaching is very rewarding for me, especially when I see a student improving.