Mercerism is a newly founded religion that is meant to actually teach people empathy. It was developed by Mercer and it provides people with a sense of what empathy really is. Isidore, Mr. Empathy, loves and constantly uses his empathy box (long story short; something Mercer made to help people share empathy and fuse in his head). Before Rick can fully develop empathy, he uses the empathy box in an attempt to understand empathy. In relation to Buster Friendly (the radio talk show host guy of the future), Mercerism conveys the struggle of control. Both Mercerism and Buster Friendly both consume the minds of humans. The author even seems to be using their conflict to show a struggle of significance. As it ends up, both Mercer and Friendly end up being frauds; however, the significance is that Mercerism has good ideas that humanity has embraced. They make like to watch Buster, but people tend to pick religion over TV and radio in the long run, and that is revealed by the battle of power between Mercerism and Buster friendly. It doesn't matter if Mercer was a fraud; he is still an important and reverent figure, and his religion really helped the characters understand and feel empathy.