The world is full of walls. Everywhere we go, there are fences, gates, partitions and other ingeniously constructed barriers—all aimed at keeping something or someone in and keeping something or someone else out. We need walls.
In the mid-1980s I attended a church that still honored “Money Sunday,” a practice begun in the 1950s. Once a year members of the congregation gathered to make financial pledges to support missions efforts. As the pledges were collected, the minister would read the amounts aloud from the pulpit: “Here’s one for $50. . . . Here’s another for $100 and one for $1,000!” Occasionally a pledge came in for, say, $10,000, eliciting all sorts of approving oohs and aahs from the congregation.
"A man had two sons . . .” was a common way to begin a parable, especially one comparing good and bad sons. Matthew uses it to contrast one son, who promises to work in the vineyard but never shows up, with another, who at first adamantly refuses to go to the vineyard but later repents and goes (21:28-32). Which one did the will of his father, asks Jesus? Not the one who talked a good game, but the one who actually followed through with obedient actions.
The unity of Christ's followers is not incidental to our salvation.