"If a writer is so cautious that he never writes anything that cannot be criticized, he will never write anything that can be read. If you want to help other people, you have to make up your mind to write things that some men will condemn." (New Seeds of Contemplation)
It's the same with preaching. The point is not to deliberately write or preach things that are controversial. That's artificial and weird. I'm finding that as I preach through the 4 Gospels, just getting to the place where the words and actions of Jesus can be heard brings us to the critical points where decisions must be made.