A repentance prayer to Baha'u'llah

“I testify, O my God, and my King, that Thou hast created me to remember Thee, to glorify Thee, and to aid Thy Cause. And yet, I have aided Thine enemies, who have broken Thy Covenant, who have cast away Thy Book, disbelieved in Thee, and repudiated Thy signs. Alas, alas, for my waywardness, and my shame, and my sinfulness, and my wrong-doing that have withheld me from the depths of the ocean of Thy unity and from fathoming the sea of Thy mercy. Wherefore, alas, alas! and again alas, alas! for my wretchedness and the grievousness of my transgressions! Thou didst call me into being, O my God, to exalt Thy Word, and to manifest Thy Cause. My heedlessness, however, hath deterred me and compassed me about, in such wise that I have arisen to blot out Thy signs, and to shed the blood of Thy loved ones, and of the dawning-places of Thy signs, and of the daysprings of Thy revelation, and of the repositories of Thy mysteries.”

http://reference.bahai.org/en/t/b/ESW/esw-1.html