Luke 13:23 - 35

Jesus teaches His followers about the way to enter His kingdom.  Not everyone who gives lip service to the King is a loyal follower; in much the same way, not everyone who claims to follow Jesus is truly a loyal follower.  Jesus invites His true followers to "enter through the narrow gate" and not miss out on the blessings of His kingdom.  The city of Jerusalem, for the most part, was filled with many who would reject Him.  Jesus mourns for this city, so great yet so greatly wicked.