Deuteronomy 4:24 (CSB) — 24 For the LORD your God is a consuming fire, a jealous God.
Moses warns Israel as they were about to enter the land that God is a consuming fire and he reiterated his exhortation that they be very careful not to forget the covenant the Lord made with them (v.23), the central character of which is the nature of Yahweh himself, who is “a consuming fire” (v.24), a jealous God,intolerant of idols in any form.
The Lord jealously consumes everything in our life that steals our affections from him and defiles the splendor of his holiness with which he has clothed us in Christ. Those who enter the LORD’s sanctuary through the veil of Christ’s flesh must come with reverence and awe:
Leviticus10:3 (NASB95) — 3 Then Moses said to Aaron, “It is what the Lord spoke, saying, ‘By those who come near Me I will be treated as holy, and before all the people I will be honored.’” So, Aaron, therefore, kept silent.
The juxtaposition of the Hebrew terms אֵשׁ(’esh, “fire”) and קַנָּא (qanna’,“jealous”) is meant to reflect Deuteronomy 6:15, where the Lord is seen as a jealous God whose anger bursts into a destructive fire. For God to be “jealous” means that his holiness and uniqueness cannot tolerate rivals to his glory; he alone must receive “glory” and “honor”.
In the body and blood of Christ we have received an even greater covenant than the one mediated by Moses; we must not, therefore, neglect this covenant:
Hebrews 12:28–29 (ESV) — 28 Therefore let us be grateful for receiving a kingdom that cannot be shaken, and thus let us offer to God acceptable worship, with reverence and awe, 29 for our God is a consuming fire.
We must enter God’s sanctuary arrayed in Christ and worship him in spirit and truth with thankful hearts washed pure in the blood of Christ and made fit as the dwelling place of God in the Holy Spirit. And we must be sure that if God’s Holy Spirit dwells in our hearts, then he burns jealously over our hearts:
James 4:5 (CSB) — 5 Or do you think it’s without reason that the Scripture says: The spirit he made to dwell in us envies intensely?
Therefore, let us offer to God acceptable worship, with reverence and awe, knowing who it is that we worship:
Origen: “God is Spirit, and those who worship him should worship in spirit and in truth.” Our God is also “a consuming fire.” Therefore, God is called by two names: “spirit” and “fire.” To the just he is Spirit; to sinners he is fire.
Biblical Reasons 