John Donne's 'Hymn to God the Father'('Hymn to Christ' in the manuscripts) has been read as a cleverly punning poem, alluding to Donne and his wife, Ann More, as it traces the path from penitence towards complete submission to Christ. This article follows the critical line that sees a more complex argument, in which the speaker tests divine mercy against the near-unforgivableness of his sins. Donne's own sermons and his familiarity with the Book of Common Prayer's provision for the Visitation of the Sick provide some evidence for his thinking on sin, confession and forgiveness. The poetic form in which he works out this relationship is examined here as both derivative and original. It bears a significant resemblance to the 'Lament' of the young Recusant, Chidiock Tichborne, executed in 1586. But it develops what is conventional, despite its poignancy, into a much riskier theological exploration. The division between public and private, the personal and the performance, in Donne's work is notoriously hard to define. He would have encountered Tichborne's poem in musical settings, and he had his own poem set to music. Izaak Walton records his response to hearing it sung in St Paul's, without noticing how, through this experience, the poet becomes the audience rather than subject of his own work. This reading concludes that there is no point in attempting a separation, and that it is the performance of confession which simultaneously brings personal resolution and makes the poem actively available to its readers.