But you shall receive power because the Holy Ghost is come upon you: and you shall be witnesses unto me both in Jerusalem, and in all Judea, and in Samaria, and unto the uttermost part of the earth. (Acts 1:8)
What did Jesus say, in John chap.14- 16, would be the work of the Holy Spirit? The work of the Holy Spirit is to reveal Jesus Christ TO us, IN us, and through us. In other words, once Christ dwells in us by joining us to Himself through the Holy Spirit, the work of that Spirit is to form Christ in us. (Gal. 4:19)
To have Christ, “formed,” in us means for Him to be, “inwardly realized or expressed.” And as Christ is formed in us, we are changed and adjusted so that we can be, “formed together with Him.” (Rom. 8:29)
Paul described to the Corinthians a little more about how Christ is formed in us. He said, “Always bearing about in our body the dying of the Lord Jesus, so that the life of the Lord Jesus may also be made manifest in our body.” (II Cor. 4:10)
Well, if Christ is formed in me and I begin to manifest Christ, then I am a witness to Him. In other words, I am EVIDENCE of the risen Christ.
You will note that the purpose of the Holy Spirit was never to take hold of us and make us to look like Jesus. The purpose was to crucify us so that Christ Himself might be seen. That is a witness of Christ – a living evidence of HIM.