Why Did Jesus Come to Earth?
Jesus said he had come to seek and save that which was lost. Adam by disobedience had lost life, the right to life, and a perfect environment to sustain life. Adam no longer reflected in his character the image and likeness of his creator as originally bestowed. He did not lose heaven, for he never possessed it, but he lost an earthly paradise in which the human race could develop and prosper everlastingly in the glorious perfection of human nature.
The Apostle Paul refers to Jesus as the second Adam, saying that as all in the first Adam die, so in the second (or last) Adam, all shall be made alive. Jesus gave his own life that the world might be rescued, given an opportunity to make a full recovery from the effects of the death sentence and be restored to human perfection. Jesus can never take back his sacrificed humanity, but God's Word testifies that he was raised to the divine nature and has a future role as Life giver to the human race, when his stated purpose will be realized: "I am come that they might have life, and that they might have it more abundantly" (John 10:10).
But one might ask: "Why have suffering and death continued so long since Jesus died for the world? Jesus intimates (Matthew 24:14) that considerable time would elapse during which the gospel would be preached throughout the world. During this 'Gospel Age' a body of faithful believers would be gathered from among Jews and Gentiles, called to follow Jesus as were the early disciples, laying down their lives in sacrifice as he did, and destined to share with him in bringing blessings to the human race in due time. These faithful ones constitute the true church, not recognized by the world in general, but known to God, their gathering being an essential feature of Jesus' work during his first advent and in the centuries that followed.