6 by purity, by knowledge, by longsuffering, by kindness, by the Holy Spirit, by sincere love,
by [in] the Holy Spirit,
Here Paul’s team showed that they did not suffer in their strength. They depended on the Holy Spirit to help them through it all.
The Holy Spirit may be a metonymy, a figure of speech whereby the cause stands for the effect. God causes spiritual fruit.
The Holy Spirit is the source that creates grace in us.
It is not our use of the Holy Spirit but His use of us that gives fruit in ministry. He will employ us in His service if we allow Him.