A lot of people have come up with a lot of equally valid ideas (some more valid than others) over time with respect to this question. God is just one possible answer, but by no means the only one or arguably even the best one. My point being that nobody has THE answer, and assuming that your guess is the correct one out of the infinite number of valid possibilities makes it statistically very improbable that you will be right. (There ARE mathematical means for selecting the most probably valid hypotheses in the absence of proof, but that doesn't really simplify the problem much.) This is why answers can only be determined by an objective and rigorous search, not declared by fiat. The problem is that I see a lot more of the latter than the former.