CCC 696 Fire. While water signifies birth and the fruitfulness of life given in the Holy Spirit, fire symbolizes the transforming energy of the Holy Spirit’s actions. The prayer of the prophet Elijah, who “arose like fire” and whose “word burned like a torch,” brought down fire from heaven on the sacrifice on Mount Carmel.1 This event was a “figure” of the fire of the Holy Spirit, who transforms what he touches. John the Baptist, who goes “before [the Lord] in the spirit and power of Elijah,” proclaims Christ as the one who “will baptize you with the Holy Spirit and with fire.”2 Jesus will say of the Spirit: “I came to cast fire upon the earth; and would that it were already kindled!”3 In the form of tongues “as of fire,” the Holy Spirit rests on the disciples on the morning of Pentecost and fills them with himself4 The spiritual tradition has retained this symbolism of fire as one of the most expressive images of the Holy Spirit’s actions.5 “Do not quench the Spirit.”6

1 Sir 48:1; cf. 1 Kings 18:38-39.
2 Lk 1:17; 3:16.
3 Lk 12:49.
4 Acts 2:3-4.
5 Cf. St. John of the Cross, The Living Flame of Love, in The Collected Works of St. John of the Cross, tr. K. Kavanaugh, OCD, and O. Rodriguez, OCD (Washington DC: Institute of Carmelite Studies, 1979), 577 ff.
6 1 Thess 5:1.