"But ye shall receive power, after that the Holy Ghost is come upon you: and ye shall be witness unto me both in Jerusalem, and in all Judea, and in Samaria, and unto the uttermost part of the earth"(Acts1:8).
As you are filled with the Holy Spirit, He dwells "upon you". He brings you into a new relationship with God and prepares you for service. The promise Jesus gave to His disciples to "receive power, after that the Holy Ghost is come upon you" had a specific purpose: "and ye shall be witnesses unto me both in Jerusalem, and in all Judea, and in Samaria, and unto the uttermost part of earth." The Holy Ghost came upon them to empower them as witnesses to the world.