Excellent, impressive, high-quality. "That sermon was fire." "Her outfit is fire." Simple strong-positive superlative. Ancestor of "the bomb"; parallel to "slay" and "lit."
Gen-Z stumbled onto biblical vocabulary. Scripture: "He makes his messengers winds, and his ministers a flame of fire" (Ps 104:4, Heb 1:7). The Holy Spirit fell as tongues of fire at Pentecost (Acts 2:3). The heart of the Emmaus disciples "burned within us" as Jesus opened Scripture (Luke 24:32). Fire is the Bible's image for genuine excellence, purifying zeal, and divine presence. Calling a Spirit-empowered sermon "fire" is theologically more accurate than the speaker realizes. Redeemable freely, with the note that Christians should be "fire" in the biblical register, not just the aesthetic one.
Gen-Z-s ordinary superlative is biblically saturated. Fire is what God sends on His people; calling excellence "fire" reaches for the right word.
The Bible's fire imagery is extensive and uniformly weighty: the burning bush, the pillar of fire, the altar fire that never went out, the tongues of fire at Pentecost, the fire that will test every Christian's work (1 Cor 3:13). Gen-Z "fire" borrows a shadow of this. Christians should not be embarrassed by the word but should carry the fuller meaning: preaching should be fire (Jer 20:9 — the word in Jeremiah's bones was "as it were a burning fire shut up in my bones"); worship should be fire (zeal, Rom 12:11); love should be fire (Song 8:6 — "the very flame of the LORD"). Be fire in the deep sense.
Hebrews 12:29 — "For our God is a consuming fire."
Acts 2:3 — "And divided tongues as of fire appeared to them and rested on each one of them."
Luke 24:32 — "Did not our hearts burn within us while he talked to us on the road, while he opened to us the Scriptures?"
Jeremiah 20:9 — "There is in my heart as it were a burning fire shut up in my bones, and I am weary with holding it in, and I cannot."
Gen-Z "fire" is biblically underdeveloped. Be fire in the biblical register: Spirit-filled, zealous, word-burning. The flame that lands at Pentecost does not stay decorative.
“That acoustic set at church last night was absolute fire.”
“For our God is a consuming fire.”