My sister and I were pretty good kids, but we did argue. A lot. About pretty much everything. So my parents, often and with great forcefulness would tell us to "Stop Arguing!" To be honest, we really didn't have that much to argue about, except my sister did take more than her share of the back seat of the car. I think, more than anything, we just got in the habit. We argued because that's what we had always done.
We weren't the only ones. The disciples had a tendency to argue among themselves, often about some of the most trivial things imaginable. They argued on more than one occasion about who among them was the greatest. In John 13:15-17, Jesus taught them a lesson they would never forget, that true greatness comes out of service.
See you Sunday!