A few points:
Steve, salvation is through Christ and has never been any other way. Before the Incarnation He was the Promise of God. Thus, Job states, "I know my Redeemer lives", and Job was before Abraham.
We don't know, by the way, WHERE Paradise or "Abraham's Bosom" was located, but it was a resting place of hope for those who died believing in that Promise and putting their faith in God and God alone for salvation/rescue/redemption. Because Jesus was the first back in heaven, they had to wait for His resurrection and ascension, but they are in heaven now.
The Old Testament sacrifices were all pictures and requirements regarding obedience to God. You will find, however, in Isaiah 1, the following:
"The multitude of your sacrifices --
What are they to me?" says the Lord.
"I have more than enough of burnt offerings,
of rams and the fat of fattened animals;
I have no pleasure
in the blood of bulls and lambs and goats.
When you come to appear before me,
who has asked this of you,
this trampling of my courts?
Stop bringing meaningless offerings!
Your incense is detestable to me,
New Moons, Sabbaths and convocations --
I cannot bear your evil assemblies.
Your New Moon festivals and your appointed feasts
my soul hates.
They have become a burden to me;
I am weary of bearing them.
When you spread out your hands in prayer,
I will hide my eyes from you;
even if you offer many prayers,
I will not listen.
Your hands are full of blood;
wash and make yourselves clean.
Take your evil deeds
out of my sight!
Stop doing wrong,
learn to do right!
Seek justice,
encourage the opppressed.
Defend the cause of the fatherless,
please the case of the widow.
"Come now, let us reason together,"
says the Lord.
"Though your sins are like scarlet,
they shall be as white as snow;
though they are red as crimson,
they shall be like wool.
If you are willing and obedient,
you will eat the best from the land;
but if you resist and rebel,
you will be devoured by the sword."
For the mouth of the Lord has spoken.
Thus, I think it is safe to say that the sacrifices were not the method of atonement, but rather it was trust and obedience given the Lord in making the sacrifices -- a dependence on Him and not on the sacrifices themselves. If this is not the case, then either the Torah or Isaiah is not telling the truth!
In the same way that James reminds us that if a man says he has faith but his actions do not show that condition of his heart, then his faith is dead -- in that same way, the actions of the Israelites regarding the sacrifices showed their submission and obedience to God. However we have no record in the Bible or in history at all of the Israelites allowing the land its Sabbaths, and for this, among other things, the Lord punished them. But over and over again He talks about their disobedience and the hardness of their hearts in the prophets, and not their lack or surplus of sacrifices.
You asked about something like John 3:16 in the OT. The promise was given to Eve, which means to all, as she was the mother of all the living. The promise given to Abraham was that ALL nations would be blessed. Job knew his Redeemer lived then. David and Agur both knew God had a Son (Psalm 2 and Proverbs 30). The knowledge was there for the people.
Did they know about the Resurrection to happen? Yes, they did.
I know that my Redeemer lives,
and that in the end he will stand upon the earth.
And after my skin has been destroyed,
yet in my flesh I will see God;
I myself will see him
with my own eyes -- I, and not another.
How my heart yearns within me!
Job 19:25-27
Therefore my heart is glad an my tongue rejoices;
my body also will rest secure,
because you will not abandon me to the grave,
nor will you let your Holy One see decay.
Psalm 16:9-10
Psalm 22 also traces the final victory after the crucifixion, as referenced by Christ Himself on the cross for His disciples, to encourage them.
It was also a story written in the stars, themselves, as the heavens truly did declare the Glory of God (which is not simply twinkling stars, but Christ Himself):
http://www.ldolphin.org/zodiac/
Blackbird, I agree with all of what you have said, but if you look at the books of Genesis, and Exodus, you will find the law was already known before Moses. However men had added so much to it (as evidenced by the Code of Hammurabi, which dates before Moses, contains some of the commandments, and yet adds innumerable detailed laws), that writing the simple form on stone was totally necessary to get people back to what God said and not just what man said (you will find Jesus was angry about this very thing with the Pharisees and teachers of the law in Matthew 23). The Sabbath was known -- look at the collection of manna. The law about murder was known -- Genesis 9. The requirement to worship God only was certainly known. Honoring one's parents, not stealing, not commiting adultery (check the Pharoah's reaction to Abraham's lie about Sarah) were all known. It's just that man messes up God's meaning so much!
