Have you ever debated a Creationist (or in my case, been a Creationist) who seems to think that all they have to do is disprove Darwinian evolution, and then they can know with certainty that God exists?
How about somebody who argues that you can't believe in objective moral values unless you believe in the Christian God?
Then there's the argument from a first cause. Christians seem to assume that without a doubt a first cause would have to be the Christian God. What if there are a cluster of gods who are the first cause, who happen to be the Greek or the Norse Pantheon?
I was talking to a friend today who made the claim at one point that not believing in God was a miserable way to live because it meant that there was no afterlife. I shot back that that was erroneous. It's completely possible that there isn't a God and an afterlife exists. The Buddhists believe that, both with reincarnation and with the concept of the pureland. It's also possible that there is a God and no afterlife exists.
It seems that most people perceive these ideas as package deals, as things which necessarily go together. But it isn't so. There is no logical connection between these ideas at all. There is just a psychological connection which comes from the dogma which we have been exposed to from birth.
Anybody have any other examples of these? I think it's useful in a debate to point out when people are using these assumptions. If you can get them to realize that what they think is not the case with these package deals, it might be easier to get through to them elsewhere.