His life will result in the reconciliation of all people on Earth with their Creator, provided they accept the offering of the gift. A gift is never much use unless it is first accepted by the recipient. It's easy to accept God's free gift to us. All that is required is you "confess with your mouth, "Jesus is Lord," and believe in our heart that God raised him from the dead, you will be saved." That can be found in the New Testament of the Bible in the book of Romans chapter 10, verse 9. Easy, peasy.
God's Christmas gift to us is the birth of His son. Our Christmas gift to God is to accept His gift. There! Your Christmas shopping is all finished!