John Donne's poem "Batter My Heart, Three-Person'd God" is religious in nature.
John Donne's early poetry was deemed "love" poetry, probably written before his marriage to Anne More. His love sonnets became more serious then, but after Anne's death, Donne began to write Holy Sonnets, some of which were more spiritual in nature. In this poem, Donne is speaking to God. Overall, he is acknowledging the Trinity (Father, Son and Holy Ghost)—aware that his earthly ways too often serve the Devil—and asks for God to renew their connection so that Donne (or the speaker) will be closer to God.
When Donne writes, "Batter my heart, three-person'd God," he is saying hit my heart hard, Father, Son and Holy Ghost. In a sense, Donne is saying that his heart has been hardened, a biblical reference to one whose heart is not open to something, the voice of reason, or (in this case), God's voice or calling. (You may recall that when Moses tries to take Israelites out of Egypt, God hardens Pharaoh's heart.) Donne continues with this thought, asking then, too, for new life ("breathe") and a mending of his soul: that as Donne rises from God's onslaught (almost like a cleansing with fire), his Heavenly father's would overwhelm Donne, break his old ways and renew his heart.
As yet but knocke, breathe, shine, and seeke to mend;
That I may rise, and stand, o'erthrow mee, 'and bend
Your force, to breake, blow, burn and make me new.
Donne then uses a metaphor, comparing himself to the people of a town that has been taken by military force and now owes its allegiance to its new leader (God), but persists in being difficult and stubborn, unable to be turned as he should be, in being "usurped." He is not faithful to his new "lord."
I, like an usurpt towne, to'another due,
Labour to'admit you, but Oh, to no end,
Reason your viceroy in mee, mee should defend,
But is captiv'd, and proves weake or untrue.
The poem shifts here, as sonnets often do at the start of the third quatrain (four-line stanza), specifically the ninth line. As the first two quatrains speak of Donne's (or the speaker's) inability to embrace the newness in a life following God, the speaker now says that despite his stubbornness alluded to previously, he really loves God, but feels tied ("betroth'd" or "promised to") God's enemy, the Devil. He asks God to break or ("divorce") him from the connection that he has with Satan, that then God will take him as a prisoner.
Yet dearley'I love you,'and would be loved faine,
But am betroth'd unto your enemie:
Divorce mee,'untie, or breake that knot againe,
Take mee to you, imprison mee…[for I…]
The rhyming couplet at the end of the sonnet (the last two lines)—which acts as a conclusion to the poem—asks that when God imprisons the speaker, He would never let the speaker be "free" of God. There is a paradox in the last two lines, as well, where the speaker notes that he will never be pure unless God "ravishes" him. In human terms, to ravish is often associated with overcoming one or taking him by force; with regard to women, the term often refers to taking them sexually by force. But spiritually, Donne is saying that unless God takes complete control of him ("ravishes" him), the speaker can never be pure (which is the opposite of being ravished, hence the paradox).
Except you'enthrall mee, never shall be free,
Nor ever chast, except you ravish mee.