That is... God is all powerful and God answers prayer by intervening in our world.
I’d like to argue that God is not all powerful. God is creator and powerful but not all powerful. Part of the reason that God is not all powerful is that God has given us power we have the power of free will power to choose for ourselves power to do what we like with no consequence that is external to the community in which we live. God created us not to worship God and not to and not be controlled by God but that we might have a relationship with God. This is not explicit in the Bible rather implicit for unless you have servant master relationship every relationship is based on negotiation whether that be two friends, partners or parent and child. There is negotiation because one party does not have all the power. And that is the nature of our relationship with God.
I'd also like to argue that God does not change our world. Rather, God changes us. This is something I've hinted at previously in my Not praying for car parking spaces and There will be no "deux ex machina!" posts. We live outside of Eden, in an imperfect world a world with floods, earthquakes and missing limbs. No matter how good it would be not to have them they are part of the reality of this world. A world is just good enough for us to suspect something very good is behind it and just bad enough for us to suspect that this is not as good as it gets. For example: We see other animals growing back limbs but yet it doesn't happen for humans. I guess for me I believe this is not as good as it gets and it won't be better until we are reconciled with each other, we are reconciled with God and that reconciliation has culminated with our return to Eden.
Finally I'd like to say the world or creation, though it doesn't seem as good as it could be, it is not evil. Far from it. Like humanity it is not what it could be and, according to Paul, groans for that final redemption.