Nooma Nooma

So we have started afternoon classes with the people from the cafe.
We are going through the book Purpose Driven Life and watching a few Nooma videos( by Rob Bell).
The videos are really key for catching the attention of the group.
There are eight of us and four of us are staff. The other four of us are the most unlikely assortment of men, one of them being Dennis. For the two days we have been doing classes he has only stayed for the video. As soon as we start talking about Jesus he leaves, but he keeps coming.
Today I started realizing that people many times live out of experiential knowledge instead of logical reasoning. It doesn't matter how many times people are told the truth or if they know it in their heads. They have to believe the truth.
So, I wonder how do you help people believe the truth. How do you provide experiences for them where things turn out differently and they can see the truth?
If we can help people believe the truth in their hearts and have good experiences will they be more motivated to make wise choices and change their lives?
I don't know. I wonder...