Holy Spirit came on the first followers of Jesus as wind and fire. Tongues of fire rested on each of them. But this is life giving fire – fire that purifies, gives warmth and light.
Holy Spirit is the presence and power of God who comes on us and into us. Holy Spirit loves God the Father and brings glory to God. Holy Spirit loves Jesus and brings us to Jesus and Jesus to us. Holy Spirit brings the words of the Bible alive as we read it. Holy Spirit transforms bread and wine, and with them all things, so that we see in them the presence of Jesus. Holy Spirit transforms us so that we become more like Jesus, filling us with love, joy, peace, patience, kindness, goodness, gentleness and self-control.
See here how the person who opens themselves up to Holy Spirit, who asks for Holy Spirit and receives Holy Spirit, becomes themselves a fire. Their hard heart becomes a heart of fire.