The Shepherds did not reason nor debate with themselves who should keep the wolf from the sheep in the mean time, but did as they were commanded and committed their sheep to him whose pleasure they obeyed.
The key word, vanity, is employed over and over to show that everything man accomplishes and achieves is empty. At his very best man is a failure. Solomon discovered this in his long march through life.
"Cranach was suggesting that the teachings of Dr Luther were more in keeping with Christ and early Christianity that that which was in vogue in Rome. While the Pope claimed Apostolic Succession, Cranach was perceptively illustrating that the truths which Luther rediscovered, were the true Apostolic Gospel. "