The essential tools of the trade for the Levitical Priesthood under the Old Covenant were knife and fire to carve up sacrifical animals, consume them upon the altar, and transform them into a pleasing aroma. Bearing that in mind, language of life under the New Covenant shows a Levitical character. Word and Spirit go to work upon believers as knife and fire preparing us as living sacrifices for God (Romans 12:1).
In Christ, we are justified, made perfect without blemish, just as all the sacrificial animals under the Old Covenant were required to be. In Christ, we are made fitting sacrifices for God our Father and are offered up through the ministry of the Word and the Spirit. The ministry of the Word, having a sharpness beyond all two-edged blades, carves us into pieces down to our very souls and spirits and expertly criticizes the contents of our hearts (Hebrews 4:12). The ministry of the Spirit consumes us (Hebrews 12:29) and transforms us (2 Corinthians 3:18) into a pleasing people who ascend by faith to God.