Mankind has been a sinner since the first man, Adam, transgressed against God and, along with Eve, was thrown out of the Garden of Eden, losing access to the tree of life.
As a result of being a sinner he is now alienated from the Holy, perfectly righteous God who made him, and who is the source of life and goodness.
Our world as we know it is now full of evil, suffering, and death. Even so, God's glory and mercy, power and perfection, are not concealed for they shine through in all of creation. And he makes a promise to all humanity of all time, that the seed of the woman would crush the one who deceived Eve in the Garden ----the serpent's head.
There is nothing that a person can do to change himself from being a sinner into not being a sinner. Nothing he can do to reconcile himself to God. Only God can do that. Only he can undo what Adam did to the hearts and souls of mankind. To do that someone must meet the full requirements of God's justice against sin in the place of the sinner. If no human can do that, as all humans are themselves sinners, who can do it?
He sent the Son , who is God of very God, eternally with God, in the likeness of mankind, to offer himself to pay their sin debt. His name is Jesus. Born of a woman as promised, a virgin, God himself his Father.
During his time as one of us the Son fulfilled all righteousness, being without sin, and was nailed to a cross to suffer and die for our sins. He substituted himself for us. What manner of love is this!
He remained in the grave for three days. God, accepting the Sons atonement for sin, raised him from the dead. For forty days he spoke with his disciples and then returned to where he had been before, to the Father, and is there at the Father's side, interceding on behalf of all those who believe and put their trust in him. He stands as a mediator between God and man, cleansing all who come to him, imputing his righteousness to them, fully reconciling them to God. By grace and through faith one is saved from the wrath of God against sin and the sinner. It is a glorious thing he has done!
One day he will return. The unbelieving will be judged and condemned because their sins have not been atoned for. Only Christ can atone for sins. There will be a new heaven and a new earth. The old will pass away and the new will come.
This is what it will be like: (Rev 21:3-6)
And I saw the holy city, new Jerusalem, coming down out of heaven from God, prepared as a bride adorned for her husband. And I heard a loud voice from the throne saying, "Behold, the dwelling place of God is with man. He will dwell with them, and they will be his people, and God himself will be with them as their God. He will wipe away every tear from their eyes, and death shall be no more, neither shall there be mourning, nor crying, no pain anymore, for the former things have passed away>" And he who was seated on the throne said, "Behold, I am making all things new." Also he said, "Write this down, for these words are trustworthy and true.: And he said to me, "It is done! I am the Alpha and the Omega, the beginning and the end."
