The world is infinite with neither end nor beginning, it has always been and always will be. Time itself is a circle always returning to the same places. This striving of the world to always meet at the same places we call the Order of Nature. Existence is as a river with no beginning or end, flowing through its banks. One must also realize with the circular nature of time, everything that has been will be again.
Humans alone were left with freewill, to a degree. We cannot change the manner of our birth or are death. Consequently neither can we change birthing our children nor killing those whom we are meant to. To give a better understanding I will use an analogy. Suppose I was to travel from Krimml to Oligarch. There are many roads I may take, but they all begin at the same place and end at the same place. Such is our lives, we have many paths we may take, but they all lead to the same places. This is how Nature keeps its order.