John Donne's poetry evolved over his lifetime from witty and cynical to profoundly religious, and also reflected his conversion from the Roman Catholicism into which he was born to Anglicanism, and his eventual ordination as an Anglican priest in 1615.
Central to Donne's notion of God is his sense of himself as a sinner, incapable of separating himself from sin by his own will, but instead requiring an act of God known by Calvinist theologians as irresistible (or efficacious) grace: the position that man's free will can ultimately not resist God's determination to save the elect. That position is expressed in Donne's Holy Sonnet:
Batter my heart, three-person'd God, for youAs yet but knock, breathe, shine, and seek to mend;That I may rise and stand, o'erthrow me, and bendYour force to break, blow, burn, and make me new.
But swear by thyself, that at my death thy SonShall shine as he shines now, and heretofore;And, having done that, thou hast done;I fear no more.