To me, Jesus was raised the Jew that He was. He knew the Law and the Prophets, and discussed them with His followers...ALL of whom were Jews. Up until that time, the Old Covenant was all they had, and it was all they’d known. But Jesus ushered in something brand new. The Old Covenant was made between God and the nation of Israel. Whereas Jesus’ New Covenant was made between God and all of the people in all of the world. Jesus fulfilled this Old Covenant, rendering it completed...“It is finished” meant just that...and He ushered in His New Covenant. Jesus’ New Covenant is what is in effect now. The appearance of Jesus and His ekklesia was intertwined with the history which had preceded it, and the Law and the Prophets were preserved for Christians in what became the Old Testament in the Christian Bible.
I'm in agreement with that as well, except that not all of Christ's audience was Jewish or Israelites. But what is your basis for discounting the Bible as a "foundation" of Christianity? Yes the OT was fulfilled, but its words are still integral to belief and faith. As a historical record alone it carries many fundamental beliefs, and the words of the prophets foretold what was to come.
