If People Could Be Saved Before Jesus, Why Was It Necessary for Him to Come?

Questions about why it was necessary for Jesus to come if people could already be justified by faith apart from works, and what the point of the Old Covenant was if God was going to make the New Covenant.  

• Since Old Testament Jews and Gentiles could be justified by faith apart from works, it seems there was already a path for salvation in place, so why was it necessary for Jesus to come?
• What was the point of the Old Covenant if God was going to make the New Covenant?