A MORTAL SIN
"And Nadab and Abihu died before the Lord," &c.
I. WHO THEY WERE THAT COMMITTED THIS SIN. Sons of Aaron; elder sons: in whom, therefore, a greater sense of thoughtfulness and responsibility might have been expected. They had also been duly anointed and consecrated. They could hardly plead ignorance and inexperience in the things of God. They had nothing else to do than attend to the tabernacle. They knew, or ought to have considered, that Jehovah had laid down instructions, even to the minutest points, as to what the priests were to do. It is a warning then to all who stand among peculiar privileges and enjoy greater light, e.g; those who live in a household where there is piety at the head, arid a continual regard in all things for the will of God (Matthew 11:20-24).
II. THE SIN THEY COMMITTED. They offered strange fire before the Lord. The fire to be used was the holy fire ever burning upon the altar (Le Numbers 6:13). To offer incense was to symbolize thanksgiving and supplication, and this, of all things, requires to be done in most careful conformity with Divine appointments. All offerings to God, to be worth anything, must be voluntary; yet even a voluntary offering may be an abomination before him when it is a random and reckless exercise of our own freedom. The highest of human actions is to do God's will with all our will, as seeing clearly that it is the right thing to do.
III. The TERRIBLE CONSEQUENCE. It was truly a mortal sin, a sin which on the very commission of it was followed by death, like the taking of some swift-working poison. It was as dangerous for a careless priest to take up the tabernacle services as for a man to take naked lights about a powder magazine. The fire of the Lord was a hidden thing, yet in a moment its full energy might be revealed, either to bless or destroy (cf. Le 9:24 with Le Numbers 10:2). But though the sin was a mortal sin, it was not in itself worse than other offences against which sentence is not executed speedily. All sin is mortal, though the deadly result be spread over long periods. This sin was punished promptly and terribly, as were some other sins in Israel, not because they were worse, but because the people, and particularly the Levites, needed a lesson in the most impressive way in which it could be given. The fire of the Lord went out against the priests here, but soon after it went out against the people (Numbers 11:1). "Except ye repent, ye shall all likewise perish."
Lessons:—A worthy office may have an unworthy occupant. There are a Nadab and Abihu here; there were a Hophni and Phinehas afterwards, and a Judas among the apostles. Anointing, consecration, imposition of hands may have official value, but God only can give the faculty of true inward service. We may bring strange fire before God when we bring zeal not according to knowledge. There may be great fire and intensity and activity with nothing of the baptism of the Holy Ghost and of fire. Consider the lamentations of Paul over his persecuting days. There is here another instance of the letter killing. In the Old Testament punishment predominated over reward, because disobedience predominated over obedience.—Y.
Numbers
Numbers 3 - numbers-3 - worlddic.com