In the gospel of Mark John the Baptist says: “I have baptised you with water, but he will baptise you with the Holy Spirit (Mark 1:8). In the gospel of Matthew he says: He will baptise you with the Holy Spirit and with fire” (Matthew 3:11b). What is the meaning of Baptism with fire?
The Baptism with the Holy Spirit, which John the Baptist had already announced (Matthew. 3:11b) and which Jesus promises in Acts 1:15 would soon begin, starts with the coming down of the Holy Spirit at Pentecost (Acts 2:1-4). Then the disciples pass on the baptism with water, which through faith in Jesus salvific work (cf. Romans 6:4) effects the forgiveness of sins and the mediation of the Holy Spirit (Acts 2:38) in Jesus name (Acts 2:41; 8:38 and others). The image of fire used by John for the Baptism instituted by Jesus (Matthew 3:11b) stresses the cleansing character of baptism. Fire is a means of cleansing that is less material but more effective than water. The Old Testament already mentions fire as a symbol for the sovereign intervention of God and His spirit which cleanses hearts and minds (cf. Isaiah 1:25; Zachariah 13:9, Malachi 3:2-3, Ecclesiasticus 2:5 etc.).