But ye shall receive power, after that the Holy Ghost is come upon you: and ye shall be witnesses. (Acts 1:8)
As we read the New Testament, we find a very simple and very plain and very forceful truth—the Holy Spirit makes a difference!
Consider the early disciples—Jesus Himself had taught them for more than three years—the greatest Bible school! But still He had to caution them and encourage them not to depend on their own wisdom and strength: “Tarry ye… until ye be endued with power from on high” (Luke 24:49b). He promised that they would receive the Person of the Holy Spirit to carry out His plan of world evangelization.
After Pentecost, the Spirit brought them a new and vivid consciousness of the actual Presence of God. He gave them the gifts of divine joy and peace. He gave them great and continuing delight in prayer and communion with God!
Finally, we recall that before Pentecost the disciples could only ask questions. After Pentecost, throughout the record in the book of Acts, they stood in the authority of the Spirit and answered all of the questions of the people concerning God’s plan of salvation through the crucified and risen Christ!