If I were you, I would be angry at letting myself believe not just a false-hood, but believing something 180° out of sync from the truth.
If you understood your pastor - or anyone else to say that Piper believes that God causes "bad things [to] happen to people because they have done something wrong", then either you - or he - misunderstood.
Piper's number one goal in life is to be HAPPY - describing himself as a Christian hedonist. What he strives to impart from his teaching is that only in God will we realize a life of satisfaction and joy. Every other pursuit that comes before our enjoyment of God, God will tear down. Why - because he hates people having fun, or because he is vindictive?
No. We will agree I'm sure that a good parent won't let their children eat nothing but ice cream. In the same way, God directs us away from meaningless pursuits and towards himself - as the ultimate satisfaction.
And sometimes, God will bring a storm, or a death, or a cancer to bring us to a point of helplessness - the bottom of relying on self. And from here we find that HE is more precious that even life or health or possessions. It's all his anyway - even our children.
Piper likes to quote this from CS Lewis:
"If we consider the unblushing promises of reward and the staggering nature of the rewards promised in the Gospels, it would seem that Our Lord finds our desires not too strong, but too weak. We are half-hearted creatures, fooling about with drink and sex and ambition when infinite joy is offered to us, like an ignorant child who wants to go on making mud pies in a slum because he cannot imagine what is meant by the offer of a holiday at the sea. We are far too easily pleased."
I think God can do that, but I God just allows bad things to happen.
It’s like any good parent, God lets things happen to us, and we have to figure out how to get through those situations.
If God was always intervening and stopping bad things, we wouldn’t grow much.
My family is suffering lots of horrible things right now: husband with cancer and possible job loss, 1 daughter with a brain injury, and my other daughter with possible degenerative movement disorder. I don’t think God has caused these events, but I do think we have to learn how to deal with the situation. I don’t know why we are having to go through these things. However, bad things happen to good people.