The title of this poem reflects a vision of God as somebody who carefully works on humans to prepare them for heaven. The word "temper" refers to the way that metal is improved by heating and cooling in order to improve its durability and elasticity. In the same way, the speaker of this poem refers to the way that God works with humans to spiritually purify and "improve" them through his control over their lives, whether that be through suffering or pleasure. The speaker is well aware of the way that he often falls so short of God's plan for his life, as he says in the opening stanzas that although he is able to be good some of the time, often he fails and falls to "hell," symbolically presenting times when he does not obey God's commands. Although he hopes to be connected with God and to end up in heaven, at the same time, he is willing to trust in God's control over his life:
Yet take thy way; for sure thy way is best:
Stretch or contract me thy poor debtor:
This is but tuning of my breast,
To make the music better.
"Stretch or contract" refers explicitly to the idea of God tempering man, and the speaker goes on to develop this image by arguing that this process is a "tuning of my breast" in order to produce more divine music. God is in control of man's life, and what man endures is meant to temper him and man's role in this process, as the final stanza makes clear, is to trust in God and his control and to allow God's "power and love" and man's "love and trust" to "Make one place ev'rywhere," symbolically erasing the distinction between heaven and hell through the force of love and man's trust in God's power. This poem therefore captures the process by which God works with man and the way man is shaped for eternity.