It’s Always Sunny in Philadelphia is a dark satirical comedy about five people who own and run a bar in Philadelphia. Most of the plots in each episode revolve around and easily solvable conflict that is made far more difficult by the character’s ignorance and stupidity. This style is often great at pointing out the absurdity of social and political issues.
For example, throughout most of the series one of the main characters, Mac, is a closeted homosexual. However, being a “devout catholic”, he is very homophobic and becomes extremely defensive when his sexuality is questioned. There is plenty of dramatic irony as Mac thinks his friends believe he is straight when in reality they all know the truth. Once he comes out officially, he is met with complete acceptance. He was the only one uncomfortable with his sexuality. In this way, the show uses satire to show how belief systems can sometimes lead to irrational thinking such as homophobia.
While the show could be seen as condemning catholisicm, it is merely trying to point out how belief systems can become so ingrained in our heads that we end up denying who we actually are. Mac always believed that he would be punished by god for coming out and kept it in for years. In this way the show is pointing out the absurdity of this mindset in hopes that people realize it is best to be themsleves.