I do not intend to deliberately offend, but shock the other party into thinking.
For example, I once had a discussion with a christian, and pointed out that their religious dogma indicates I will go to hell. I asked them why they are so cruel, wanting me to go to hell. They said they did not want me to go there, and I pointed out that they support that position because they support that god and associated dogma. I recommended they find and worship a god less cruel.
The best thing you can do for a person and the worst thing you can do to a religion is to get people to actually think.