When we look at Jesus' life, we don't think only of His death at Calvary, but also of His whole life where He presented Himself to the Father fully saying,"A body Thou hast prepared for Me.....and I have come to do Thy will O God (in this body)" (Heb.10:5,7). Jesus never once did His own will in His body but only the Father's. This is what it means to offer oneself as a burnt offering to God. This is what Paul exhorts us also to do in Romans 12:1. "Present your bodies a living and holy sacrifice to God....that you may prove what the will of God is" - exactly as Jesus did. This burnt offering was presented to God and burnt completely. The Bible says this was "a soothing aroma to the Lord" (Lev.1:17) - meaning something that God was very pleased with - "This is My Beloved Son in Whom I am well pleased."(Matt.3:17). Paul said that his life's ambition too was to "please the Lord" (2 Cor.5:9).
When we present our bodies to the Lord, it is very easy to say, "Lord, I give my body totally to You." But we don't know whether we have offered it all, until we "cut it up". We could be deceiving ourselves. What does it mean to cut it up and offer it piece by piece - as was done with the burnt offering? It means that we offer our bodily parts piece by piece to God.
We say, "Lord, here are my eyes. I have used them for the devil and for myself for the past many years, looking at and reading many things that offend You. But I am laying my eyes on the altar now. Never again do I want to use these eyes to look at or read anything that Jesus would not look at or read. I never want to sin with these eyes any more."
We go next to the tongue and say, "Lord, here is my tongue. I have used this tongue for the devil and for myself for so many years, speaking whatever I liked, telling lies for my own gain, getting angry at people and gossiping and backbiting against others and accusing them. But I never want to do all that any more. Here is my tongue Lord. It is yours from this moment onwards - totally and completely."
We go next to our hands and our feet and our bodily passions, one by one, and say the same thing: "Lord, here are the members of my body and my bodily passions, with which I have sinned and hurt You. Never again do I want to use these to please myself or to satisfy my lusts. They are all Yours."
It is only as we cut each piece and lay them on the altar one by one, that we discover whether we really are offering our body totally to God or not. When the offering is cut into pieces and laid out on the altar fully, then you can say, "Now, Lord, let Your fire fall on the sacrifice and consume it." We read in Leviticus 9:24 how the fire of God fell upon the burnt offering and consumed it. That fire is a picture of the baptism in the Holy Spirit and fire that comes to consume our sacrifice and to set our bodies on fire for God. But the fire never fell until every last piece of the burnt offering was placed on the altar.
What do Christians do when they don't want to pay the price of yielding their bodies as a burnt offering and yet want to get the fire? They manufacture a false fire - a counterfeit one. And that is what we see in Leviticus 10:1,2: "Nadab and Abihu, the sons of Aaron took fire pans and put fire in them and offered strange fire before the Lord which He had not commanded them." When we don't have the real fire of God, and we want to be a part of those who have the real fire, the danger is that we can imitate what they have so as to be able to say, "Yes, we also got the fire. We also spoke in tongues!" God was so angry with Nadab and Abihu for imitating the real fire that He sent down another fire from His presence - this time not to consume the burnt offering but to consume these two hypocrites!
It is dangerous to imitate the real thing in spiritual matters. Yet, multitudes of Christians are doing this these days. They are being coached by preachers to speak in tongues, to work up their emotions and to experience psychosomatic "healings" (imagining that these are the same as being healed "in the Name of Jesus.").
Those who have obtained the real fire from God have paid a price for it. They laid everything on the altar of God - their money, their eyes, their tongue, their hands, their all. They examined their lives and made sure that every piece of the burnt offering was on the altar; and God sent His fire on them. You watch the life of such a man, and you wish you had the same powerful anointing. But you are not willing to pay the same price for it and you still want to show others that you are anointed. It is then that you can do what Nadab and Abihu did - produce strange fire, work up your emotions, manufacture "tongues," etc. Since more than 95% of believers don't have spiritual discernment, you may be able to fool them that you have the real fire. But you know better than anyone else that what you have is self-produced and not from God. Beware! If God were to judge Christendom today in the way He judged Nadab and Abihu, I am sure that a lot of Christians would die.