When time was fulfilled - Jesus came.
Since the expulsion from Paradise, since the Fall of Man, mankind is situated in a miserable condition: Envy, greed and aggression motivates its conduct.
Confiscation, suppression and war are the result. They will be guilty, and guilt calls for atonement.
The first Adam causes all this, but the last Adam will bring salvation: This is Jesus. Jesus brings us essentially three things:
1.) He takes the dept from our account.
2.) He prevails over the death. So we will live.
3.) He conciliates us the guidance by the Holy Spirit, the Spirit of God.
And this is valid also for Non-Jewish people. The curtain in the Temple of
Jerusalem, the curtain to the Most Holy, is torn. Therefore we have direct access to God himself - by his Spirit.
We may talk to him directly, and He talks to us, we can be guided by Him in our
doings.