And while staying with them he ordered them not to depart from Jerusalem, but to wait for the promise of the Father, which, he said, “you heard from me; for John baptized with water, but you will be baptized with the Holy Spirit not many days from now” (Acts 1:4-5).The disciples needed the power that only the Holy Spirit could provided. The Spirit is the One who would enable the disciples to be witnesses--heralds of the good news of Jesus. Apart from the work of the Spirit, the disciples ministry would have been ineffective. And the same is true for us. We must not rely on our own knowledge, abilities or strength as we seek to bring the good news to others. We need the power that only the Spirit supplies.
But you will receive power when the Holy Spirit has come upon you, and you will be my witnesses in Jerusalem and in all Judea and Samaria, and to the end of the earth (Acts 1:8).