MA says that Jesus and the Father (God) are one so the Old Testament and the New Testament should agree as Jesus is also the Father yet the Son denies the Father's words (the Old Testament). Either the Son and the Father are not One or either the Old Testament is false or the New Testament is false.
If God is Eternal the Old Testament should be Eternal Testament why become Old and be revised with the New Testament? It comes down to God not capable of Eternal Testament. Jesus can't be God as he failed to give his testament first and make it the Eternal Testament.
Old Testament also foretold of Lucifer which Jesus fulfilled in New Testament.