Nadab and Abihu

Aaron seems to have had liberty to enter within the veil at all times, until after the death of two of his sons, Nadab and Abihu. They had offered “strange fire before the LORD,” and fire had gone out from the Lord and devoured them (Lev. 10:1-2). On other occasions, fire from the Lord had been the unsparing judgment sent upon sinning ones — fire as a symbol, ever speaking of judgment (Num. 11:1; 2 Kings 1:5-16). The case of Nadab and Abihu is very full of significance. Fire from God had come down and consumed the burnt offering upon the altar, showing God’s judgment upon the victim, and yet His acceptance, when the fire had done its work, for this was a sweet savor offering. This fire, and no other, must be used in the burning of the incense; the sweet fragrance of Christ must go up to God through the judgment that has fallen upon Him. The bruising brings this out in its fullest sweetness — “bruised for our iniquities.”
Nadab and Abihu did not use this fire, and fire from God fell upon them instead of upon the victim. In the words of another, “These two eldest sons of Aaron should have taken coals of burning fire from off the altar — fire which had come from the Lord. But instead of this, they put fire in their censers which was common to them, but strange to the Lord. May we not regard this as another form of Cain worship? Cain offered an offering without the shedding of blood. His was a religion of works, though the name of the Lord was in it. His was not the worship of a false God, but it was false worship of the true God — worship which was not preceded by salvation. Nadab and Abihu were quite correct as to censer, incense and the holy place, but they did not recognize that it was the fire from God which had fed upon the sacrifice, and that no fragrance could come up to God from the hands even of His priests, unless through the sacrifice consumed in judgment upon the altar. Christ may be owned as the true Christ. He may even be confessed with the lips as the Son of God. Prayer and worship may be conducted in His name, but unless His death be acknowledged and trusted in the way of atonement... the worshipper, whoever he be, is offering strange fire, mingled though it be with the name of Christ.”
Sin having thus been brought into the holy place, Aaron was restricted in his entrance into the holiest, and when he went, it must be in the “fine linen” garments. At other times he moved about in the holy place bearing on his shoulders and on his breast the names of Israel engraven on the precious stones, those on the breast and those on the shoulders being inseparably bound together; and the golden plate on behalf of others adorned his forehead.