The Lord established the Christian Church through His life on earth and the Emperor Constantine adopted Christianity as the faith of Rome. However, Constantine convened the Council of Nicaea in 325 AD, which changed the trajectory of Christianity and made it necessary for the Lord to come again.
This prophecy of the peaceable kingdom taught the children of Israel that a future time of peace would come when there would be no enemies to fear. It also taught that a little child would come to lead them.
Shepherds near Bethlehem kept watch over their flocks at night when the heavens opened and an angel stood before them. They believed the angel's message right away, went to see the baby Lord and spread the news with joy.
Only the humble in heart were prepared to receive the Lord at His birth. The shepherds represent all good people who receive the knowledge of the Savior joyfully and with a burst of heavenly light.
Simeon and Anna the prophecies of the Lord's advent to be fulfilled in their lifetimes. Each gave thanks when the Lord opened their spiritual eyes to see Him in the temple.