Theologically, though, the shirt isn't that far off. Paul wrote about the nature of the church, which he compared to a human body in 1 Corintians:
But in fact God has arranged the parts in the body, every one of them, just as he wanted them to be. If they were all one part, where would the body be? As it is, there are many parts, but one body.I doubt that the makers of this t-shirt had this passage in mind. I suspect the folks at The Church You Know website are bloviating about the state of the church in America (or their perception of it, at least). In any event, it's pretty satirical stuff. They even have a Wally the Worship Leader android for sale.
The eye cannot say to the hand, "I don't need you!" And the head cannot say to the feet, "I don't need you!" On the contrary, those parts of the body that seem to be weaker are indispensable, and the parts that we think are less honorable we treat with special honor. And the parts that are unpresentable are treated with special modesty, while our presentable parts need no special treatment. But God has combined the members of the body and has given greater honor to the parts that lacked it, so that there should be no division in the body, but that its parts should have equal concern for each other. (1 Corinthians 12:18-25, NIV)