What now was the purpose of Leviticus? In general, as regards Israel, it was given to direct them how they might live as a holy nation in fellowship with God. The key-note of the book is "Holiness to Jehovah." More particularly, the object of the book was to furnish for the theocracy set up in Israel a code of law which should secure their physical, moral, and spiritual well-being. But the establishment of the theocracy in Israel was itself only a means to an end; namely, to make Israel a blessing to all nations, in mediating to the Gentiles the redemption of God. Hence, the Levitical laws were all intended and adapted to train and prepare the nation for this special historic mission to which God had chosen them.
To this end, it was absolutely necessary, first of all, that Israel should be kept separate from the heathen nations. To effect and maintain this separation, these laws of Leviticus were admirably adapted. They are of such a character, that obedience to them, even in a very imperfect way, has made the nation to this day to be, in a manner and degree perfectly unique, isolated and separate from all the peoples in the midst of whom they dwell.
The law of Leviticus was intended to effect this preparation of Israel for its world-mission, not only in an external manner, but also in an internal way; namely, by revealing in and to Israel the real character of God, and in particular His unapproachable holiness. For if Israel is to teach the nations the way of holiness, in which alone they can be blessed, the chosen nation must itself first be taught holiness by the Holy One. A lesson here for every one of us! The revelation of the holiness of God was made, first of all, in the sacrificial system. The great lesson which it must have kept before the most obtuse conscience was this, that "without shedding of blood there is no remission of sin;" that God therefore must be the Most Holy, and sin against Him no trifle. It was made, again, in the precepts of the law. If in some instances these seem to tolerate evils which we should have expected that a holy God would at once have swept away, this is explained by our Lord (Matt. xix. 8) by the fact that some things were of necessity ordained in view of the hardness of men's hearts; while, on the other hand, it is certainly quite plain that the laws of Leviticus constantly held before the Israelite the absolute holiness of God as the only standard of perfection.
The holiness of God was further revealed by the severity of the penalties which were attached to these Levitical laws. Men often call these harsh, forgetting that we are certain to underestimate the criminality of sin; forgetting that God must, in any case, have rights over human life which no earthly ruler can have. But no one will deny that this very severity of the law was fitted to impress the Israelite, as nothing else could, with God's absolute intolerance of sin and impurity, and make him feel that he could not trifle with God, and hope to sin with impunity.
And yet we must not forget that the law was adapted no less to reveal the other side of the Divine holiness; that "the Lord God is merciful and gracious, and of great kindness." For if the law of Leviticus proclaims that "without shedding of blood there is no remission," with equal clearness it proclaims that with shedding of blood there can be remission of sin to every believing penitent.
And this leads to the observation that this law was further adapted to the training of Israel for its world-mission, in that to every thoughtful man it must have suggested a secret of redeeming mercy yet to be revealed. Every such one must have often said in his heart that it was "not possible that the blood of bulls and of goats should take away sin;" and that as a substitute for human life, when forfeited by sin, more precious blood than this must be required; even though he might not have been able to imagine whence God should provide such a Lamb for an offering. And so it was that the law was fitted, in the highest degree, to prepare Israel for the reception of Him to whom all these sacrifices pointed, the High Priest greater than Aaron, the Lamb of God which should "take away the sins of the world," in whose person and work Israel's mission should at last receive its fullest realisation.