On Maundy Thursday the Creator of the universe bent down to his knees to wash the dirt from the callused feet of his followers. And as he scrubbed away the dirt, he scrubbed from his Bride all possible justifications for ethnic and economic hierarchies. He radically upset cultural norms. And now he calls us to go low in foot-washing-like service to one another.
But most importantly, Maundy Thursday reminds us the Son of Man willingly came to earth as a lowly slave, to serve us, to be crushed for us, to free us from the sin slavery that leads to eternal death. On his knees Jesus enacts for us a parable of the cross.
The disciples could not yet see the symbolic anticipation. The full explanation for why Jesus washed their feet would only become clear after the blood-bought atonement on Good Friday. Then the disciples would look back and understand the act of deep humility in the cross that brought us a once-for-all, head-to-toe, cleansing from all our sin.