Luke 12:49-51 is sobering.  Does verse 49 refer to the destruction or fire before judgment?

Jesus said, “I came to cast fire on the earth, and would that it were already kindled!  I have a baptism to be baptized with, and how great is my distress until it is accomplished!  Do you think that I have come to give peace on earth?  No, I tell you, but rather division” (Luke 12:49-51).

Contextually, he was speaking about when he returns (Lk. 12:39-40ff), so it’s understandable at first glance to think that the “fire” of verse 49 refers to either the fires of hell (Rev. 21:8) or the fires that would consume the world and universe on Judgment Day (2 Pet. 3:10ff).  However, if that were the case, why would Jesus wish, even before he had fulfilled his mission to save us from our sins, “that it were already kindled”?  It doesn’t make sense for Jesus to wish that hell or the end of the world had already taken place even before his death and resurrection; that would contradict the clear biblical doctrine of his great love for us and desire for us to be saved.

Thus, “fire” has to have a metaphorical meaning.  This also would fit the context, because his subsequent mention of his upcoming baptism (v. 50) is also clearly metaphorical since John had already literally baptized him.  The baptism which he had yet to be baptized with, the one which gave him great distress until it was accomplished, is clearly a metaphorical reference to his upcoming “baptism” (immersion) of suffering on the cross (cf. Mk. 10:38).  In like manner, the fire he now speaks of is also metaphorical. 

Fire is often used metaphorically in Scripture to refer to a cleansing agent or purifier (cf. Mal. 3:2; Is. 4:4).  Trials of life such as persecution can often be used by God to spiritually cleanse us or purify us (cf. James 1:2-4).  Considering that Jesus immediately speaks metaphorically of his own upcoming trial (v. 50), and then follows it by referring to the trials of division that his followers would endure (vs. 51-53), it’s likely that he was metaphorically referring to the trials that would come upon his disciples, the “fiery consequences” of being a faithful Christian.