1 Thess 5:19 cautions us against suppressing the work of the Holy Spirit. The Holy Spirit is the third Person of the Godhead and, as such, His activity cannot be suppressed unless it serves the divine purpose. He can be grieved and His work suppressed in the lives of the saints because the Lord has called us to work out our own salvation in fear and trembling while acknowledging that He is at work in us, giving us the will and ability to do so. However, if we are genuinely His children and suppress His work, discipline will ensue.