In this nine-line poem, Frost's speaker states his opinion that the world will end because of human emotion, not natural disaster. The two emotions that are in contention to destroy the earth are desire (which could also be understood as greed) and hate.
Frost's speaker puts his money on desire, which he likens to a fire, as what will bring on the earth's demise, saying:
I hold with those who favor fire.
However, his speaker does not discount hate, which he aligns with ice, stating:
But if it had to perish twice,
I think I know enough of hate
To say that for destruction ice
Is also great
There is a Biblical quality to these two destructive vices. What comes to mind first is the Biblical book of James in the New Testament, in which James asks the Christians at the beginning of chapter 4:
What causes fights and quarrels among you? Don’t they come from your desires that battle within you? You desire but do not have, so you kill. You covet but you cannot get what you want, so you quarrel and fight.
Hate is also condemned throughout the New Testament as a destructive force, so much so that we are told to love our enemies and do good to those who hate us.
Frost's speaker puts the safety and well-being of the earth in human hands, saying we are responsible for preserving it. To do so, we need to control our more destructive emotions. The speaker shows that he has an intimate knowledge of the dangers of both hate and desire, implying that these are feelings that reside in every human heart, much as we might wish to deny them in ourselves.