I've written things about God's plan before. I'm not going to link those posts here (because I don't remember exactly when I wrote them, and I'm too lazy to go look). Anyway, the gist of it all is that I think that sometimes we take the idea of God's plan too far, as in, we start to see everything as an act of God; thus reducing God to some divine puppet master and as puppets, it reduces our free will as well. I stand by that, because I can't see God causing someone to choose drunk driving, leading to someone else's death. I can't accept that God sends a tornado through a town and kills people with it. And so forth. It's not exactly what people mean when they chirp, "It's all a part of God's plan", but sometimes I think the meaning can devolve to that on some level.
However, I am feeling led to rest in the tension of the "both...and" right now. People of God are often called to become comfortable in the tension of paradox. On the one hand, God is not a puppet master pulling the strings. He is not directing natural disasters, nor causing sins and mistakes that cause pain and suffering. On the other hand, He does have a plan, in and through all of it. It is all a part of His will. Even if we make a distinction between what He actively plans for our lives and what He allows to happen in a fallen world that can lead us forward, it is all His will.
I am thinking of a friend of mine who lost her 2 month old a year ago. I cannot possibly think that God would actively cause a baby to die like that. However, if my friend's suffering is not in some mysterious way a part of His plan, then that would make it meaningless. It cannot be meaningless. Her child's life, his death, her suffering and that of her family, and his life now in heaven are full of meaning, purpose, and redemption. In some mysterious way that I cannot begin to understand, it is a part of His will, and a part of his plan.
Likewise, when something extremely good comes out of the midst of sin, it's hard to understand. How can a good God's plan include sin? Again, it comes to the "both/and". It is never His will for someone to sin, but His grace can still abound in the midst of that. His saving plan is not threatened by that sin. It can still be His will that things happened the way that they do.
I don't fully understand it all. I just know that if I am going to be able to trust God fully, I have to see His will in all of it. Every messy piece of it. Not as a puppet master, but as a loving Savior, who is redeeming it all.