But ye shall receive power, after that the Holy Ghost is come upon you: and ye shall be witnesses unto me both in Jerusalem, and in all Judaea, and in Samaria, and unto the uttermost part of the earth. ~ Acts 1:8 (KJV).
Every Believer needs power to function effectively in carrying out Kingdom assignments, which basically entails being witnesses for Jesus Christ.
The Kingdom of God is result oriented, and until we as believers manifests these results, it might be difficult for the world to believe us. Jesus Christ said in the book of John 4:48 “Except ye see signs and wonders, ye will not believe”. The world we live in right now is filled with a lot of doubting thomases who will not believe until they see results.
For us to manifest the mysteries of God in achieving results in our various kingdom assignments, we must desire the Holy Ghost, because until we experience His presence, we cannot manifest His power.
In the book of Luke 3:22, the Holy Ghost descended upon our Lord Jesus Christ, and this experience was critical to the fulfilment of His ministry here on earth. Also, in the book of Acts 1:4, Jesus Christ asked His disciples not to depart from Jerusalem, but wait for the gifts of His Father, which is the gift of the Holy Spirit.
However, as believers we must desire the gifts of the Holy Spirit, if we are to be effective witnesses for our Lord Jesus Christ. We must desire to receive, because what you do not desire, you cannot experience.
May you receive the power to be effective witnesses for Jesus Christ, after the Holy Ghost has come upon you.