Hebrews 9 has taught us that the New Covenant, which is Jesus’ last will and testament, came into effect through the cross. While it is true that a will is given power by death, it is also true that time is needed to circulate the will’s contents and to carry out the terms of the will. It usually takes time for an official meeting to make known the contents of the will. Then it takes time for specific terms of the will to be put into practice. Such matters are seldom simple and speedy.
We see something like this in the case of Jesus’ will, the New Covenant. All that the Jews of Jesus’ time had ever known was the Old Covenant. On the day Jesus died, did all believers understand the full meaning of His death? Did they make all of the practical changes implied by the New Covenant? Obviously not, for the disciples were confused by Jesus’ death. Only after Jesus’ resurrection were they able to understand His explanation. “He opened their minds to understand the Scriptures” (Luke 24:45).
It was not until the giving of the Holy Spirit on the Day of Pentecost that the basic terms of Christ’s will were announced publicly (Acts 2). Even then, the disciples had much to learn. The Holy Spirit inspired Peter’s preaching (John 14:26; Acts 1:8; 4:8). By inspiration, Peter revealed that God welcomed all people (Acts 2:39). Yet Peter himself may not have understood the full implication of that truth, for it took special miracles by God to convince Peter to accept Samaritans and Gentiles into the church (Acts 8 and 10).
Previously Jesus had said, “I still have many things to say to you, but you cannot bear them now. But when the Spirit of truth comes, He will guide you into all the truth” (John 16:12-13). Jesus understood human limitations. He well knew that the disciples were not able to receive everything in one instant—even from Him, the Master Teacher. The changes were so great that it would take time, and the special guidance of the Holy Spirit, eventually to reveal everything to them.