One of the most popular images of Jesus is as the "good shepherd" (cf. Psalm 23:1-3; John 10:14-15). And while that metaphor of a good shepherd carrying his lambs and gently leading the others to still waters certainly conveys the love God has for us, the "serious shepherd" should convey the same the thing. Because shepherd imagery was often used of kings. King Cyrus of Persia is called a shepherd in Isaiah 44:28. King David too in Psalm 78:71-72. Even the uninterested counselors of King Herod told him after their encounter with the wise men before Jesus was born that they should be looking for a serious shepherd king of Israel. In Matthew 2:6 they quoted Micah 5:2 saying, "Out of you [Bethlehem] will come a ruler who be the shepherd of my people."
Jesus readily embraced the serious shepherd role as well in Matthew 25:31-32 when he said, "When the Son of Man comes in his glory, and all the angels with him, then he will sit upon his glorious throne. All the nations will be gathered in his presence, and he will separate the people as a shepherd separates the sheep from the goats." Which probabaly sounded to some an awful lot like what Ezekiel 34:17 said hundreds of years earlier. "And as for you, my flock, this is what the Sovereign LORD says to his people: I will judge between one animal of the flock and another, separating the sheep from the goats."
As we near Christmas, and remember that Jesus came the first time to lead us like a good shepherd, it would be wise of us to remember that one day soon He will be returning as our serious shepherd. To finish what He started. And reward those who have been his good and faithful servants. Isaiah 40:10 says it this way, "Yes, the Sovereign LORD is coming in power. He will rule with a powerful arm. See, he brings his reward with him as he comes. He will feed his flock like a shepherd. He will carry the lambs in his arms, holding them close to his heart. He will gently lead the mother sheep with their young." Aren't you glad Jesus is a good but serious shepherd?
For more info on Jesus as shepherd, see the book Sitting at the Feet of Rabbi Jesus p.46