The fullness of the Holy Spirit is exemplified through the person of the Holy Spirit. The Holy Spirit is a person that help the saints fulfill God’s plan in the earth. He was sent to the earth after Jesus’ death, resurrection and return unto Heaven to indwell the saints to help them do the work of the ministry. Before Jesus’ birth, death and resurrection, the Holy Spirit was operating in the earth realm but not in the fullness of his ministry. In the Old Testament only the Jews enjoyed the ministry of the Holy Spirit. Their Priests, Prophets, Judges and reliable Kings were endowed with the Holy Spirit to help and assist the Israelites. This represented a small portion of the human population.
But, after Jesus’ death and resurrection he told his disciples that it was needful for him to go away so that he could send them the comforter, which is the Holy Spirit, back to them. So, there was a spiritual release of the fullness of the Holy Spirit into the earth realm after Jesus went back to Heaven. This fullness of the release of the Holy Spirit was manifested in Jerusalem on what is referred to as the day of Pentecost.
The day of Pentecost is when the Holy Spirit was sent from Heaven to approximately one hundred and twenty (120) individuals that were obeying Jesus and tarrying in an upper room where the disciples were staying in Jerusalem. They were praising, blessing and believing God for the promise of the Holy Spirit on one accord, when all of a sudden they heard the sound like a mighty rushing wind fill the room and they all began speaking in other tongues.
When this news was spread around town, devout Jewish men representing every nation came to witness this phenomenal event. They were surprised to hear the unlearned disciples speaking in different foreign languages and they questioned the meaning of this miracle. But, the Prophet Joel in the Old Testament had prophesied about this day of Pentecost in Joel 2:28-29. He stated, And it shall come to pass afterward, that I will pour out my spirit upon all flesh; and your sons and your daughter shall prophesy, your old men shall dream dreams, your young men shall see visions: And also upon the servants and upon the handmaids in those days will I pour out my spirit.
So on the day of Pentecost, God poured out his spirit on the Jews and not long after that he poured it out on other ethnic groups as well. In Acts 10:44, God sent Apostle Peter to preach to a group of Italians and while Peter preached to them, God poured out his spirit on them. This released the fullness of the Holy Spirit’s work into the earth. Now, when any individual gets saved, he can ask God to fill him/her with the Holy Spirit and God is more than willing to give this gift to his children so that they may fulfill the great commission and go into all the world and preach the gospel.