[RCL] Isaiah 50:4-9a; Psalm 31:9-16; Philippians 2:5-11; Luke 22:14-23:56 or Luke 23:1-49 Palm Sunday is an invitation of the most extreme kind. If you picture a polite and proper written invitation to an important event, it’s usually on pretty, white paper and arrives quietly in your mailbox with a diffident request for an RSVP. Palm…