Differences in the Old [Mosaic] Covenant and New Covenant

What are the differences between the Mosaic national covenant God made with ethnic Israel and the New Covenant that God made with spiritual Israel, which include Jews and Gentiles?

The following passage shows the Mosaic covenant blessings were based on keeping the covenant conditions of the Law of Moses….. 
(Exodus 19:5-6 ESV) Now therefore, if you will indeed obey my voice and keep my covenant, you shall be my treasured possession among all peoples, for all the earth is mine; and you shall be to me a kingdom of priests and a holy nation. These are the words that you shall speak to the people of Israel.”

The following similarly worded passage shows that New Covenant blessings are based on God’s sovereign grace and the only covenant condition is faith…..

(1 Peter 2:9 ESV) But you are a chosen race, a royal priesthood, a holy nation, a people for his own possession, that you may proclaim the excellencies of him who called you out of darkness into his marvelous light.

For ethnic Israel it was IF YOU OBEY……  For spiritual Israel it is YOU ARE A CHOSEN RACE…..  Old Covenant blessings were based on obedience to the Law of Moses, while New Covenant blessings are based on God’s grace through faith alone.  Membership into the Mosaic Covenant was through physical birth and Jews remained in the Mosaic Covenant whether or not they became believers.  New Covenant membership is through spiritual birth [regeneration] and all that are included are born again believers.  There was then and is now a small portion or remnant of ethnic Israel who became believers and are part of spiritual Israel. 

Whether one is Jew or Gentile, spiritual salvation does not come through groups.  It comes on an individual basis and is based on individual saving faith.  The only people in Israel today or in the future that will receive any spiritual blessings are those who are spiritually redeemed through personal faith.  Gentiles with saving faith receive the same blessings as Jewish believers.  Paul states this fact clearly in Ephesians 3:6: “This mystery is that the Gentiles are fellow heirs, members of the same body, and partakers of the promise in Christ Jesus through the gospel.”

The Mosaic [Old] Covenant was temporary and has ended.  The New Covenant is everlasting and is the fulfillment of all the promises made to Abraham.  Abraham looked forward to a heavenly City of God and not a strip of land in Canaan as Heb. 11:10 points out: For he was looking forward to the city that has foundations, whose designer and builder is God.  Although most of the Israelites delivered from Egypt died in unbelief without seeing it, the physical land God promised Abraham was fulfilled when the Israelites under Joshua conquered Canaan.  The spiritual Promised Land, a new heavens and new earth, will be realized by Abraham’s spiritual seed in the eternal state after history has ended.

The redeemed spiritual people of God include both Jew and Gentile believers but not the entire ethnic nation of Israel.