This cup means the new covenant by virtue of my blood. This is taken from Luke 22:20.
When does the new covenant go into effect? Not when Jesus made reference to it on his last night on Earth. For it to go into operation, Jesus’ blood had to be poured out and its value had to be presented to Jehovah in heaven. Moreover, the Holy Spirit needed to be poured out on those who would be “joint heirs with Christ.” This is taken from Romans 8:17.
Hence, the new covenant went into effect at Pentecost 33 C.E. when Jesus’ loyal disciples were anointed with Holy Spirit. Though the former law covenant was in since made “obsolete” when Jehovah announced through Jeremiah that He would conclude a new covenant with Israel, it did not actually end until the new covenant went into effect. Hebrews 8:13 tells us: “In his saying “a new covenant,” he has made the former one obsolete. Now what is obsolete and growing old is near to vanishing away.”
When that happen, God could view both Jewish and uncircumcised Gentile believers in the same light, since their “circumcision is that of the heart by spirit and not by the written code.” This is taken from Romans 2:29.