I am come to send fire on the earth; and what will I, if it be already kindled?

I came to cast fire upon the earth; and what do I desire, if it is already kindled?

"I came to throw fire upon the earth, and what is my desire? Oh that it were even now kindled!

I came to send a fire on the earth, and it may even now have been lighted.

I have come to cast a fire upon the earth. And what should I desire, except that it may be kindled?

I am come to send fire on the earth. From these concluding words it may easily be inferred, that this was one of Christ's latest discourses, and is not related by Luke at the proper place. But the meaning is, that Christ has introduced into the world the utmost confusion, as if he had intended to mingle heaven and earth. The gospel is metaphorically compared to fire, because it violently changes the face of things. The disciples having falsely imagined that, while they were at ease and asleep, the kingdom of God would come, Christ declares, on the contrary, that there must first be a dreadful conflagration to kindle the world. And as some beginnings of it were even then making their appearance, Christ encourages the disciples by this very consideration, that they already feel the power of the gospel. "When great commotions," says he, "shall already begin to kindle, this is so far from being a reason why you should tremble, that it is rather a ground of strong confidence; and, for my own part, I rejoice that this fruit of my labors is visible." In like manner, all the ministers of the gospel ought to apply this to themselves, that, when there are troubles in the world, they may be more diligently employed in their duty. It is proper to observe, also, that the same fire of doctrine, when it burns on all sides, consumes chaff and straw, but purifies silver and gold.

I am, come - The result of my coming will be that there will be divisions and contentions. He does not mean that he came "for" that purpose, or that he "sought" and "desired" it; but that such was the state of the human heart, and such the opposition of people to the truth, that that would be the "effect" of his coming. See the notes at Matthew 10:34.
Fire - Fire, here, is the emblem of discord and contention, and consequently of calamities. Thus it is used in Psalm 66:12; Isaiah 43:2.
And what will I - This passage might be better expressed in this manner: "And what would I, but that it were kindled. Since it is "necessary" for the advancement of religion that such divisions should take place; since the gospel cannot be established without conflicts, and strifes, and hatreds, I am even desirous that they should come. Since the greatest blessing which mankind can receive must be attended with such unhappy divisions, I am willing, nay, desirous that they should come." He did not wish evil in itself; but, as it was the occasion of good, he was desirous, if it "must" take place, that it should take place soon. From this we learn:
1. That the promotion of religion may be expected to produce many contests and bitter feelings.
2. That the heart of man must be exceedingly wicked, or it would not oppose a work like the Christian religion.
3. That though God cannot look on evil with approbation, yet, for the sake of the benefit which may grow out of it, he is willing to permit it, and suffer it to come into the world.

I am come to send fire - See this subject largely explained on Matthew 10:34 (note), etc. From the connection in which these words stand, both in this place and in Matthew, it appears as if our Lord intended by the word fire, not only the consuming influence of the Roman sword, but also the influence of his own Spirit in the destruction of sin. In both these senses this fire was already kindled: as yet, however, it appeared but as a spark, but was soon to break out into an all-consuming flame.

(13) I am come to send fire on the earth; and what will I, if it be already kindled?
(13) The gospel is the only reason of peace between the godly, and so it is the occasion of great trouble among the wicked.

I am come to send fire on the earth,.... Meaning either the Gospel, which is as fire, that gives both light and heat, warms the hearts of God's people, and causes them to burn within them; though very distressing and torturing to wicked men; so the word of God is compared to fire, in Jeremiah 20:9. Or else zeal for it, and which would be opposed with sharp contentions by others; or rather persecution for the sake of the Gospel, called sometimes the fiery trial; which tries men, as gold is tried in the fire, what they are, and what their principles and profession be; unless the Holy Ghost, and baptizing with him, and with fire, should be meant; since Christ in the next verse, speaks of the baptism of his sufferings, which that was to follow:
and what will I? what shall I say concerning this fire? what shall I wish and pray for? what would be pleasing and agreeable to me? even this,
if it be already kindled; or "that it were already kindled", or "O that it were already kindled"; meaning either that the Gospel was warmly preached by his disciples, and zealously defended by them, as it was after his death and resurrection; or that hot persecution was raised against it which was now beginning, since the advantage of it would be far greater than the evil in it: or that the Holy Ghost was come down in cloven tongues, like as of fire.

to send--cast.
fire--"the higher spiritual element of life which Jesus came to introduce into this earth (compare Matthew 3:11), with reference to its mighty effects in quickening all that is akin to it and destroying all that is opposed. To cause this element of life to take up its abode on earth, and wholly to pervade human hearts with its warmth, was the lofty destiny of the Redeemer" [OLSHAUSEN: so CALVIN, STIER, ALFORD, &c.].
what will I, &c.--an obscure expression, uttered under deep and half-smothered emotion. In its general import all are agreed; but the nearest to the precise meaning seems to be, "And what should I have to desire if it were once already kindled?" [BENGEL and BLOOMFIELD].

I am come to cast fire on earth. Conflict and persecution. This was the effect of preaching the gospel. It aroused opposition. See notes on Matthew 10:34-37.
If it is already kindled. The conflict had already begun. The enemies were seeking his death.

I am come to send fire - To spread the fire of heavenly love over all the earth.