Michael's primary argument is from "personal experience". Kind of a "you'll know it is true if you believe it is true" statement or of the "if you felt what I felt, you wouldn't deny it" kind. It is an interesting argument to make as it really provides no reason for others to follow such. I don't doubt that people have had these "awesome" religious "experiences" but I wonder why someone would present such a self-centered argument. (If the "experience" wasn't a regular "christian" one, people would be institutionalized - like those claiming to be "god" or that voices were telling them to do things.)
I have had dreams in my life that seemed extremely real and could have been (mis)construed as religious experiences or experiences of an after-life. They, however, were neither. They were dreams or delusions. We all have them and there is good reason for it.
Richard Dawkins, almost 3 years ago, addressed, with great eloquence, the argument from personal experience and it is truly worth reading.