war in Heaven long time ago when Lucifer, the choicest of God'd angels, wanted to take God's throne in a coup attempt he launched with his converts. He was later on called the Satan or the Devil and, after his forces were defeated, he exiled himself away from God's Heavenly Kingdom. The struggle between the forces of Good and Evil began since then.
It was evident from the very beginning that God permits us to use and exercise our free will. He could have destroyed Satan forever in that war in Heaven but yet He allowed him to roam for a time to follow his chosen path. No wonder why in the Garden of Eden, although He has given Adam and Eve His instruction, He allowed them to freely choose which fruit of the tree to be eaten and which fruit of the tree that was forbidden. Disobedience from God's instruction, as the result of Satan's deception to the first human beings, paid a very high price.
Right after Adam and Eve's fall at Eden the ultimate plan for redemption was already set up. There must be a sacrificial lamb, a ransom to reconcile man with God once and for all. It was told in Genesis 3:15 about Christ's role being the fulfillment of a Divine Promise for Redemption and to finally destroy Satan by crashing him in the head, as what was God warned the serpent: "and I will put enmity between you and the woman, and between your seed and her seed; he shall bruise you on the head, and you shall bruise him on the heel."
Christ symbolism appeared many times in the Bible long before he was actually born. The High Priest Melchizedek, whose origin was unknown, resembled much of Christ when he took bread and a cup of wine just like what Jesus did in the Last Supper with his disciples (Genesis 14:18-20): "and Melchizedek king of Salem brought out bread and wine: and he was [is] the priest of the Most High God. And he blessed him (Abram who later named as Abraham), and said, 'Blessed be Abram to the Most High God, possessor of heaven and earth, and blessed be the Most High God, which hath delivered thine enemies into thy hand'. And he gave him tithe from all." During the time of Moses, when the Israelites were wandering around the desert and serpents attacked them, God instructed him to make a fiery serpent and set it on a pole (Numbers 21:8): "The Lord said to Moses, 'Make a snake and put it up on a pole; anyone who is bitten can look at it and live.'"
Christ's birth was prophesied by the Prophets especially Isaiah but most of the people during that time and also after that failed to recognize about the importance of such a prophecy and, even in the time of the Messiah's birth, they failed to recognize him. How lucky we are today because we have Christmas to celebrate about. We must, therefore, radiate to others the true meaning of Christmas so that all our hearts will be filled with much love, joy, and understanding. Christ will finally destroy the Evil in the End of Days.