"Jesus instituted a "new covenant" or religious act, at the Last Supper."  Absolutely right.  But there had to be an "old covenant" before there could be a new covenant.  The Old Testament, from Genesis 3:15, 16, through Psalms 22, Isaiah 53 and through all the prophets to Malachi is a Scarlet Thread pointing to God's Messiah.  My question to you is, have you ever received God's Messiah in to your life and asked Him to extend His saving Grace?