The indwelling Holy Spirit helps us to share Christ with others. The Lord promised this in John 15:26,27: "When the Comforter is come, whom I will send unto you from the Father, even the Spirit of truth, which proceedeth from the Father, he shall testify of me: and ye also shall bear witness, because ye have been with me from the beginning."
The Holy Spirit confirms to us what is true about Christ, and we in turn share those truths with others.
If the Spirit of God is responsible to convict the world of sin, He must first of all convict us of sin because we are the ones He indwells--we are the tools He will use.
He not only makes the life of Christ real to us, but He also causes us to understand our own sinfulness. We can do little to impress others with the awfulness of sin if we ourselves are not acutely aware of our own sinfulness.
This is possibly one basic reason why the world is not convicted of sin, yet is bound for hell at an accelerating speed.
We are the key to the world's conviction and conversion. This is why we need to be controlled by the Holy Spirit. Only as we are completely surrendered to Him can He use us to convict people around us of sin, righteousness and judgment.
It is necessary for us to surrender completely, not for personal enjoyment but so the Father's work in the world might be done in and through us.
"Blessed is the man unto whom the LORD imputeth not iniquity, and in whose spirit there is no guile" (Ps. 32:2).