How Were Second Temple Era Jews Saved? Was Such Salvation Automatic?

 I don't really know for sure what Christians believe about how salvation operated in the past.  However, I've heard some say that to be saved the Jews had to obey the law perfectly.

Does anyone else think that sounds like a ridiculous, unworkable system?  Why did G-d go through the trouble of arranging a sacrificial system that would be unworkable?  Isn't that the old bait and switch?

From what I've heard, the Christian response is that the old sacrificial system was instituted to show how we need Yeshua and not sacrifices of animals.  This is a clever response but it ignores an important Biblical truth and also portrays G-d as a sadist who enjoys making Israel perform acts of futility.

The truth ignored by many Christians is that, historically, G-d was able to impute righteousness (i.e. save) individuals prior to Yeshua:

"And he [Abram] believed in the Lord and he [the Lord] counted it to him for righteousness," (Genesis 15:6).

This doesn't say that Abram became inherently righteous but rather that righteousness was imputed to him.  The legal effect of this imputation is that Abram experienced what we refer to as "salvation."  He could walk with G-d and have a relationship with Him because G-d had somehow extended His own Righteousness (Jeremiah 23:6 "Adonai Tzidkenu", "The Lord OUR righteousness").

Was this salvation automatic for all of Israel as long as the High Priest made the atonement on Yom Kippur?  The Torah says of Yom Kippur: 

"This is to be a lasting ordinance for you: Atonement is to be made once a year for all the sins of the Israelites.”

But if it was automatic then how did the Rich Man in the parable of "The Rich Man and Lazarus" go to hell as punishment for his sins?  

So let's go to the question:

QUESTION 42:

How Were Second Temple Era Jews Saved?  Was Such Salvation Automatic?