Since the birth of Jesus in 5 B.C., however, the planet as a whole has only experienced the briefest periods of peace. What happened? Were the angels lying? Did Jesus fail to bring the utopian world of peace touted to lowly shepherds working near Bethlehem?
Since the human manifestation of the Prince of Peace (Isaiah 9:6), the earth has seen not a decrease but a steady increase in the consequences brought by conflicts and wars. Six out of the top ten bloodiest conflicts in human history have occurred since 1800 A.D. The twentieth century's two world wars combined caused untold suffering and the death of at least 100 million people (Wikipedia article on War).
One of the striking ironies of history is that while humans long to live peaceably with each other they ultimately plan and prepare for the next conflict. Through the eyes of a Biblical cynic, the angelic proclamation recorded in Luke 2:14 seems to be nothing more than naive wishful thinking.
What did Jesus teach?
Incredibly, Jesus never taught that his birth, ministry, or sacrifice would bring tranquility to the globe. He, on the contrary, revealed the exact opposite! Jesus revealed to his disciples, just before the beheading of John the Baptist in early 29 A.D., the following startling fact.
Do not think that I have come to bring peace on the earth; I did not come to bring peace, but a sword (Matthew 10:34, HBFV).
The Lord, several months later, felt it necessary to correct any misconceptions his disciples, and humanity in general, might entertain regarding the goals of his ministry. Speaking less than six months before his crucifixion he stated the following.
Do you think that I came to bring peace on the earth? No, I tell you, but rather division . . . Father shall be divided against son, and son against father; mother against daughter, and daughter against mother (Luke 12:51, 53, HBFV).
Less than a week before his crucifixion the Lord gave his well-known Mount Olivet prophecies. He revealed that peace would be a rarity for humanity until his return (Matthew 24, Mark 13 and Luke 21). In fact, he prophesied that humans, in the End Time, would experience such a high level of conflicts, wars, trials and sufferings that, if left unchecked by God, would lead to the end of ALL human life!
When will it come?
The peace promised by God, made possible through Christ, will fully come to the earth (and the entire universe) in stages and at a time of His choosing. All those who have, or now are, called and converted have already been granted this state spiritually as a gift from the Eternal.
Those who repent, have their sins forgiven and possess the Holy Spirit receive spiritual peace with God and within themselves (John 14:27, Romans 5:1, Philippians 4:7). This is in spite of the fact that they still have to endure trials and tribulations brought to them by the world (John 16:33).
Jesus' Second Coming, with his resurrected saints, will usher in God's kingdom for 1,000 years (Revelation 20:4). Humans living during this period, however, will still have to repent and accept His sacrifice for their sins in order to be spiritually at one with the Father.
A few more events must also take place before all creation experiences the perfect fulfillment of peace promised in Luke 2:14. God will judge and permanently remove from his creation all those, including Satan the devil, who willfully chooses to be his enemy. He will accomplish this task through the lake of fire (Revelation 19:20, 20:10, 14 - 15).
The Eternal will then create a new universe where only those who are righteous will dwell (Isaiah 65:17, 66:22, Revelation 21:1). He will then place his and Jesus' throne within a New Jerusalem and move the glorious city to our recreated planet (Revelation 21:2 - 3). It is then, when heaven and earth become one, that perfect peace will exist forever!