The Greek word being translated to "bring" is βάλλω (ballō). According to the lexicon, this word means, "to throw or let go of a thing without caring where it falls; to scatter, to throw, cast into."
And the word "earth" here is being translated from the word γῆ (gē) - which means "arable land" or "the earth as a whole - as opposed to the heavens."
The reality is Jesus is speaking metaphorically about the physical world - those of us who dwell within - and are focused upon - the material world. Thus a more appropriate translation of this statement would be something like:
"I have come to cast fire within the material world, and how I wish it were already kindled!"So how was Jesus going to cast fire into the material world?
Because he was delivering the teachings coming from the Supreme Being:
“My teaching is not my own. It comes from the One who sent me." (John 7:16)These are the teachings that instructed us that we are not these physical bodies and we are not of this world. Jesus' teachings were that we are each children of the Supreme Being and thus the only way we will become happy is if we re-develop our eternal loving service relationship with Him.
He came to teach us that we are like fish out of water without our relationship with the Supreme Being.
And how can this teaching "cast fire" into the physical world?
Because - for those who hear and follow them - Jesus' teachings can burn away the illusion that we will be happy by chasing our self-centered materialistic dreams around. Jesus' teachings have the ability to obliterate the concept that if we just get that next thing - be it more money, tasty food, some sex or fame - we will be satisfied and happy.
Jesus specifically taught that these things - related to the temporary physical body - do not bring happiness:
“Therefore I tell you, do not worry about your life, what you will eat; or about your body, what you will wear." (Luke 12:22)Jesus' teachings specifically instruct us to focus our lives on the Supreme Being and the realm of the spiritual, where the Supreme Being is the center:
"And do not set your heart on what you will eat or drink; do not worry about it. For the pagan world runs after all such things, and your Father knows that you need them. But seek His kingdom, and these things will be given to you as well." (Luke 12:29-31)The phrase "seek His kingdom" is mistranslated. The word "kingdom" indicates a physical place, as though we would be seeking to live in heaven or something. Rather, the Greek word translated to "kingdom" here is βασιλεία (basileia). The lexicon specifically states the word does not mean "kingdom" - "not to be confused with an actual kingdom but rather the right or authority to rule over a kingdom."
Rather, the meaning of the word is "royal power, kingship, dominion, rule." And because Jesus specifically said "His" - referring to the Supreme Being, Jesus is speaking of accepting the Supreme Being's authority and power and dominion over our lives.
Taking shelter or refuge in God
In other words, Jesus is speaking of taking shelter of the Supreme Being. He is speaking of surrendering ourselves to the Supreme Being, who is our Best Friend and Constant Companion.
This is how the material world - the self-centered drive to please ourselves by serving our physical bodies - is burned up. By accepting Jesus' teachings by focusing our lives on the Supreme Being and taking shelter of Him. This is why Jesus' most important teaching was:
" 'Love the Lord your God with all your heart and with all your soul and with all your mind.' This is the first and greatest commandment." (Matt. 22:37-38)