I have come to set the earth on fire, and how I wish it were already blazing! There is a baptism with which I must be baptized, and how great is my anguish until it is accomplished!Luke 12:49-50
Fire refines gold and silver to perfection (Zechariah 13:9; Revelation 3:18). The earthen treasures of the Creator, rusted by sin and corruption, await the conflagration of the Spirit of God.
…fire symbolizes the transforming energy of the Holy Spirit’s actions… Jesus will say of the Spirit: “I came to cast fire upon the earth; and would that it were already kindled!” In the form of tongues “as of fire,” the Holy Spirit rests on the disciples on the morning of Pentecost and fills them with himself.Catechism of the Catholic Church 696
The body of clay assumed by the Son of God will be dipped and submerged (baptizó) in the flames of his Passion and death to release the blazing energy of the Spirit.
Clay kindled by the Spirit’s fire lives forever.
I came to cast fire upon the earth,
To kindle clay and bring it to birth.