This generation is an evil generation; it seeks a sign, but no sign will be given it, except the sign of Jonah. Just as Jonah became a sign to the Ninevites, so will the Son of Man be to this generation.
The lectionary provides complementary readings for our reflection: a passage from the Book of the Prophet Jonah and Jesus' remarks about "the sign of Jonah."
In Saint Matthew's Gospel the "sign" is Jonah's three days in the belly of a fish, which may parallel Jesus' lying in the tomb until the third day.
Saint Luke ignores that suggestive idea and calls our attention to the Ninevite response to Jonah's preaching. Every one of them, from the king to the slave -- including the domestic animals -- fasted, wore sackcloth and ashes, and begged God for mercy.
Jonah "became a sign" as Jesus is a sign; their prophetic warnings must be heard.
Jonah's message to the Ninevites was plain and simple, "Forty days more and Nineveh shall be overthrown." They heard his word and responded.
I have heard of such moments in history when a prophetic word was immediately welcomed. The Irish had grown weary of their continual fighting in the name of opposing gods when Saint Patrick and his people arrived. Armed only with the Word of God he converted the nation to Catholicism. Secondly, natives of the crumbling Aztec Empire saw the image of the Virgin on a cactus-fiber tilma and underwent Baptism. Though the new Spanish rulers were no less oppressive than the old, the natives welcomed the Mother of a kindlier God.
I suspect scrupulous historians could say it wasn't quite that simple in either case; but, for the story-telling preacher, there are parallels with the legend of Jonah and the Ninevites. Sometimes people are ready for a new god.
All that being said, we come to the bottom line, "... there is something greater than Jonah here."
Lent reminds us that we must repent. No one among us can claim to be good enough; no one dare say "I have turned my entire life over to the Lord and there is no shadow of sin within me."
Saint John warns us,
If we say, “We are without sin,” we deceive ourselves, and the truth is not in us. If we acknowledge our sins, he is faithful and just and will forgive our sins and cleanse us from every wrongdoing.
That invitation is too good to pass up.
"In the old days" many Catholics routinely confessed their sins once a month; some, weekly. They recognized the value of habitually confessing even minor sins so as to avoid greater temptations. Entire families approached the sacrament; sometimes with a bit of coaching from each other. If a child complained he had nothing to confess, his mother helpfully reminded him. And that suggestion reminded her of her overreaction to the child's behavior. Meanwhile, the married couple examined their interaction.
It was not a foolproof system -- no system is -- but it helped; marriages remained intact and children survived childhood to become responsible members of a prosperous nation.
Lent reminds us it's not too late to call on the Mercy of the Fatherwho gave his only Son, so that everyone who believes in him might not perish but might have eternal life.