The fear of the Lord

Some ramblings on the love and fear of God:
We all know that God is love.  Did the Israelites know that?  God is unchanging, the same yesterday, today, and forever.  But his dealings with the Israelites were through a bunch of laws.  He said he would show love to a thousand generations of those who loved him, and punish only to the third and fourth generations of those who did wrong, which he did.  But could they really see that God was love, even in the midst of the law, and that God was interested in changing their hearts, and not just in governing their way of life?
I've heard that Jews don't see the law as a burden, so maybe as an outsider looking in I'm misunderstanding this, but Jesus seems to have made God's heart for relationship a lot clearer through the New Testament than God did in the Old Testament.

My main point is this: I'd like to come to be a better understanding of a full dimensional God who is understood in the New Testament reality, but through the lens of the Old Testament.