I'm not sure that it's possible to understand the full import of Biblical footwashing until you've walked around Beira in flip-flops. There is dust everywhere. There is garbage everywhere. And those aren't even the really nasty things. Add to that the fact that sweat makes all of the dirt stick to your skin, and you're no longer surprised to find that it's fairly normal for a person to take several baths a day.
As I stood in the shower, watching the brown water swirl around my toes, I marveled at the fact that, if Jesus were here, He would be washing my dirty, stinky feet. He'd be down on the floor with His basin and towel, and I, like Peter, would say, "No, Lord! That's no job for You to do! I'm too dirty."
"If I do not wash you, then you have no part with Me."
God doesn't look down from Heaven and see us wallowing in our sin and say, "Well, they blew it. Time for plan B." Nor does He compromise His holiness with our filth. He encounters us where we are, surrounded by sewage and rebellion and despair, and He washes us. He pours His own blood over us to make us clean.
In holiness so perfect that He cannot associate with my sin, and love so profound that He does not tolerate our separation, He washes my dirty feet so that I may sit with Him in heavenly places.