There are so many different religions, poets, and writers who have discussed this subject; so, it would be necessary for you to consider all different types of sources before settling on one answer for yourself. Consider reading the major books of all major religions and gather the most information that you can so you can answer this questions for yourself. The topic of God is a spiritual one, so the answer might be spiritual. If you are Christian, you would consult books like the Bible. If you believe in Allah, you would consult the Quran, right? If you don't know where to start because you don't believe in anything right now, consider all of the sources in your research just like you would for any class that requires a research paper. I think that discovering the answer for yourself through in-depth study is the way to go. Here are some links for you that might help you on your journey.
well said and explained!! but it will be better if you research this and get a deeper take on this!
there is much more to this as the poster above has mentioned.