1. God is the creator of everything. He created the heavens, the earth and EVERYTHING in them, Including mankind. God created all animals, but when he created man (Adam), God breathed his breath into him. So, man is a spiritual being. Animals are not. God created a woman (Eve) from man to be a help mate. So, we have one man, Adam and one woman, whom God created. God created them to live forever. However, God warned them not to eat of a certain tree in the garden that he created for them. God warned that they would die (suffer spiritual separation & death) if they disobeyed God.
2. Adam and Eve disobeyed God with a lot of help from that snake the devil. When Adam and Eve sinned they brought spiritual death upon themselves and all of us. Their sin caused a devastating affect to come upon the entire earth. God is absolute holiness and sin can not dwell in his presence. So, man became spiritually separated from our creator. Thus man's sin nature doomed him to hell; and all humans ever born has that sin nature in them.
3.God instituted a process that temporarily covered man's sin. He did it through the nation of Israel. However, that system was not sufficient. God then did what he prophecies when Adam and Eve sinned. He promised a Messiah would be born who would save mankind from sin. The birth of Jesus is the fulfillment of God's promise to provide a permanent way back to a correct relationship with him.
4. Jesus' birth is only part a of the way back to spiritual, everlasting life with God. Just as innocent, spotless lambs were used in animal sacrifice Jesus was the innocent, spotless lamb of God who gave his own life as a sacrifice to totally "wash" and cleanse away our sin. That was part b. When Jesus gave himself (shedding his own innocent blood) to die on the cross. He did it for all of mankind. That is, all those who will accept his gift of salvation. What a wonderful Saviour!
5. Salvation is not automatic. Each person must believe on Jesus Christ and accept the gift in order to be saved. Do you accept the gift? If you do, admit you're a sinner and lost in your present condition. Repent. Which means you turn your life around and go in the opposite direction. No more living in sin. You will no longer live a life of sin. Tell God that you accept the gift he gave us, the Lord Jesus Christ and his finished work on the cross. When you sincerely do so, God will change your heart. You will become a new creature in him. God, the Holy Spirit will help you overcome sin. He will teach, guide and comfort you. You will want to live for him and do his will. Share God's gift with others and help them come to know him and to accept his gift.
One sweet day God will bring things in this age to an end, he will physically restore the earth to it's once perfect state. God will receive us unto himself. We will be forever with him. We will walk with the Father and commune with him face to face as he intended from the beginning.