One common problem 21st century American Christians face is that we don't understand how much we have in Jesus; therefore we try to add things to Jesus in order to bring satisfaction. The same type of thing was going on in the early church. So, when Paul wrote the book to the Colossians, it was because people were trying to add things to Jesus. But he doesn't just blast them and go after these other issues. Instead, he reminds them of how much they have in Christ so that they realize, "Wow, we don't need anything else. I have more than enough."