Here is a post on the difference between the Old and New Covenants by Joel over at Grace Roots blog. I liked it so much I wanted to post it here:
Heb 10:9 "He takes away the first that He may establish the second."
"About this New Covenant: This is not "Old Covenant, Part 2." This is not a continuation of the Old Covenant. This is not a mixture of two Covenants. This is not a "new" way to do the same old thing. This is not an amendment to the Old Covenant. This is not "picking up where the old left off." This is a completely different covenant. This is "a better covenant, which was established on better promises." (Heb 8:6)."The old system of a priesthood of mortal men (see Heb 7:23-25 "prevented by death from continuing"), and everything that went along with it, served a purpose under that old covenant, but it is now done away with. The old tithing system that was set in place to provide for the Levites, widows, orphans and strangers, served its purpose under that old covenant, but it is now done away with. All of the sacrifices, which had a purpose under that old covenant, have now been done away with.
"The curse of the law has been done away with. In fact, the Law has been "wiped out," "taken out of the way," "nailed to the cross." (Col 2:14). Did Paul really say that? YES HE DID! Trying to be obedient to God's Law has been done away with. Man's relationship with the law altogether has been done away with! One has to be dead to the law in order to be married to a completely different spouse, Jesus Christ. (Rom 7:1-6, Gal 2:19-20). They are not the same, and you cannot be married/joined to both.
"God's law was "a shadow of of the good things to come, and not the very image of the things" (Heb 10:1). It, along with the sacrifices, could never make anything perfect and could never take away sins, but really only brought about a reminder of sins! (Heb 10:2-4).
"However...JESUS HIMSELF - the PERSON - is the reality, is the substance (Col 2:17). The reality/substance is not a system of rules and laws and sacrifices, but is a Person. Jesus' one-time, once-for-all sacrifice did away with ALL of that! With one sacrifice, the system of laws and ordinances was done away with, as was the entire priestly system and the entire OLD COVENANT. "What the law could not do, in that it was weak through the flesh, God did by sending His own Son in the likeness of sinful flesh..." (Rom 8:3). Jesus Himself became a curse for us (Gal 3:13) and became sin for us (2 Cor 5:21). With one sacrifice, Jesus TOOK AWAY the sin of the world! "Behold, the Lamb of God who takes away the sin of the world!" (John 1:29). "But now, once at the end of the ages, He has appeared to put away sin by the sacrifice of Himself" (Heb 9:26).
"If we want to live in the fullness of the reality of Jesus Christ, we need to get out of the shadows and instead focus on the substance - the Person of Jesus Christ who IS our life and who is our light. He Himself IS the reality of the abundant life."
Joel Brueseke