Acts 1:1-2 In the first book, O Theophilus, I have dealt with all that Jesus began to do and teach, (2) until the day when he was taken up, after he had given commands through the Holy Spirit to the apostles whom he had chosen.
On the Mount of Transfiguration the message for the three apostles was to listen to Jesus Christ and in the first sentence of Acts we are told they listened as Jesus gave commands through the Holy Spirit to his chosen apostles right up to the day of His ascension. Jesus was going to build his Church through his apostles and it was important for them to listen just as God had instructed. They were His agents for starting and nurturing this completely new entity, The Church of Jesus Christ. This was more than a new administration of an existing covenant. This was a new covenant fulfilling and replacing the old covenant [see devotionals #20 through #25 on Hebrews 8:8-13].
Focus on Christ #55