The word 'grace' appears 8 times in the Old Testament (NIV) and then jumps to 123 appearances in the New Testament. Wonder why that is? Why the increased focus on grace in the New Testament?
To me, the answer is Jesus. The story of Jesus is the obvious difference between the Old and New Testaments; but just not his story, but what his story means. Jesus suffered and died that we may live forever in glory. The grace we have been given (and need) has been given to us through what Jesus did and nothing to do with what we have done or will do.
The word 'grace' gives me great comfort in that my salvation isn't in my hands, but has already been claimed through Jesus Christ.