Because God made you for a reason, he also decided when you would be born and how long you would live. He planned the days of your life in advance, choosing the exact time of your birth and death.
I'm having a hard time with this concept. This is part of that problem I have with ascribing everything that happens to divine plan. It takes free will out of the picture. If I do certain things that are disobedient to God, I can actually cause my own death before His appointed time. And what about the affect of other people's disobedience? God may intend me to live to be 90, but if someone else exercises free will and murders me, what does that say about God scheduling my days? Then again, I guess that's why I need to be living close to His heart and actually pray for His mercy and protection.
Yet at the same time, I have always acknowledged that God has shaped me using every event in my life. I would be such a different person without those things! But how much of it is His design, and how much is His allowing things to happen and working through them for good even though they were not in His design?
I don't think God is just a puppeteer. The Bible is full of examples where He acted in response to various things: people's prayers, people's disobedience, His own observations... I don't know that He plannned every single human being at the beginning of time. I think He created us with the ability to create physical life, and He gave a command to do it. The fact that He gave "man" that responsibility also implies that He gave us choice in whether to do it or not to do it. That doesn't mean it's totally up to us--He listened to many women in the Bible who could not conceive. The parents supply the genetic material, but God decides which genes to use.
This doesn't really make things much clearer, but it is something I can see. It's sort of like when I left AU. I think now that His design was for me to stay there. But I chose to leave, and there were other places where He knew He could use me. Of course, my decision wasn't without a price, and I've paid it. But I think that He is still accomplishing His purpose in me and shaping me into the reflection of Him that He wants me to be. I don't know how He's going to finish it, but I do know that if I will yield to Him, He will.