Simple question, I'm sure that the answers will not be so simple.

This is a question that I've forgotten the answer to. A quick Google search did not immediately bring about anything that turned the lightbulb on.

What were the mechanics behind His death and our salvation?

Following the line of the "why it's impossible to be Catholic" thread...

God gave the Jews the Law to follow as a means to reach their salvation. It was painfully obvious the Law could not be followed, so over the course of some hundreds of years various prophets were sent telling of the coming of something greater.

Jesus, the second person of God, had to come to us as a fully human entity to die a human death so that He could rise. If he doesn't die that death then there is no New Covenant for us through Him. Bear in mind, His humanity shows through when He asks God to "take away this cup", but His ultimate obedience wins out with, "but according to Your will."

The human form of God had to die and rise for all of humanity to reach salvation through our own deaths.

Really the answer can be fairly simple, but you could also make it a lot more complex.


Simply put,
1. God basically says, "you can get to heaven if you don't sin"  or "If you sin I will crush you".  Also the Old covenant - "keep all of these rules, do these sacrifices,etc... and I won't crush you, and I will bless you"
2.  We sin. We do not keep all of the rules, and have a tough time with all of the sacrifices.
3.  According to God's law, the punishment for our sin is death.  Not keeping the rules and sacrifices is punishable by death.  W
4.  We have no recourse.  Because we've sinned and are guilty, we can't just go to God and plead our case, we cannot just say "hey look, we tried, but can't do it, please don't crush us"
5.  Jesus is born.  He is fully God and fully man.  He is also perfect.  Never sins, never fails to do as God asks.
6.  Because Jesus has not sinned, he can go to the "gates" of Heaven.  The impassable gates that previously kept you and I out.  He throws open the gates.  For the first time in history, the gates can be opened by a Man, because that man was perfect.  
7.  He then "bargains" with God, saying "Father, place their guilt, and the punishment for all of their sin on ME"  and they will then no longer be guilty.(he is able to take all of this guilt, and stand in our place, because he is fully God) and able to bargain with God, because he hasn't done anything that God could find him guilty for.
8.  In that act, Jesus essentially opens the door to heaven for us, and nullifies the requirements of the old covenant.  At the last supper, He then issues us a new covenant,  where all that we have to do for our end is to partake in Him, to fulfill our end.
9.  So the old covenant was fulfilled because Jesus was able to bargain with God on our behalf, and change the rules.


With all of that said, here is a great passage from about 350 years ago from John Flavel's  "The Covenant of Redemption between the Father and the Redeemer"

The TORAH (law) was given to all of Israel. The tribe of Judah, as well as the other 11 tribes, plus those who sojourned with them, in a covenant relationship. It was never a means for salvation, but for blessings. Obedience brings blessings, while disobedience brings curses. Salvation came for them, the same as it does for us, by believing that our Father provides the unblemished Lamb, whose precious blood redeems us of our sins, just like Abraham believed, and it was counted to him as righteousness. Sacrifices are a picture of the shed blood of our Messiah covering our sin, going all the way back to the Garden, when animals were sacrificed to cover Adam and Chava (Eve), after their sin.
Sacrifice is actually a poor translation of the Hebrew word corbon, which actually means drawing near.

Whoops, wrong thread.

The following is from carm.org, it is great resource to help you understand christianty

Jesus became sin for us and bore our sins in His body on the cross, thus fulfilling the Law.
2 Cor. 5:21, "He made Him who knew no sin to be sin on our behalf, that we might become the righteousness of God in Him."
1 Peter 2:24, "and He Himself bore our sins in His body on the cross, that we might die to sin and live to righteousness; for by His wounds you were healed."
Rom. 8:3-4, "For what the Law could not do, weak as it was through the flesh, God did: sending His own Son in the likeness of sinful flesh and as an offering for sin, He condemned sin in the flesh. 4in order that the requirement of the Law might be fulfilled in us, who do not walk according to the flesh, but according to the Spirit."
Therefore, salvation is by grace through faith since it was not by our keeping the Law, but by Jesus, God in flesh, who fulfilled the Law and died in our place.
Eph. 2:8-9, "For by grace you have been saved through faith; and that not of yourselves, it is the gift of God; 9 not as a result of works, that no one should boast."
Gal. 3:13, "Christ redeemed us from the curse of the Law, having become a curse for us - for it is written, "Cursed is everyone who hangs on a tree."
Eph. 5:2, "and walk in love, just as Christ also loved you, and gave Himself up for us, an offering and a sacrifice to God as a fragrant aroma."

Read more here.  carm.org/questions/about-jesus/why-did-jesus-have-die-our-sins