Shane Claiborne tells this story in his book The Irresistible Revolution.
Several decades ago a group of families were kicked out of an apartment complex in Philadelphia without a place to go. They were left to fend for themselves on the city streets.
The families occupied an unused sanctuary in a Catholic cathedral. Many local leaders wanted to oust these families from the abandoned cathedral, but college students joined the families in an attempt to keep the authorities at bay.
The families and students won. They stayed in the cathedral until they were able to find homes.
The families hung this banner over the door of the cathedral:
“How can we worship a homeless man on Sunday and ignore one on Monday?”