'Don't be silly,' said the Devil in her heart. 'You have been as good as saved all your life. You have always wanted to do right. How can you expect such a sudden change as if you were a great big drunkard? It's absurd.' 'But my _heart_ is as bad as the heart of a big sinner,' cried poor Katie in an agony of fear. 'I have been as bad inside, if not in my outward actions and words.' And then she took hold of God in faith. 'Lord, I must be converted. I cannot rest till Thou hast changed my whole nature; do for me what Thou dost do, for the thieves and drunkards.' But for six weeks it seemed as if God did not hear her cry. She grew more and more unhappy. All her past sins rose before her: those bursts of temper when she was at school, those wrong thoughts and feelings. Yes, the Bible was true when it said: 'The heart is deceitful above all things and desperately wicked.' Katie argued, too, like this: 'I cannot recollect any time or place where I claimed Salvation and the forgiveness of my sins; if God _has_ saved me, He would surely have made me certain of it. Anyway, I must and will know it. I must have the assurance that I am God's child.' Unable to rest, she would pace her room till two o'clock in the morning, and would lie down at last, with her Bible and hymn-book under her pillow, praying that God would Himself tell her that her sins were forgiven. At last, one morning, as she woke, she opened her hymn-book, and read these words:-- My God, I am Thine, What a comfort divine, What a blessing to know that my Jesus is mine. Now she had read and sung these lines scores of times before, but they came this morning with a new power to her soul. 'I am Thine!' 'My Jesus is mine!' she exclaimed. 'Lord, it is true!--I do believe it! My sins are forgiven. I belong to Thee!' and her whole soul was filled with light and joy. She now possessed what she had been seeking all these weeks--the assurance of Salvation! And then what do you think she did? She threw on a wrapper, and, without waiting to dress, hurried across to her mother's room, and tapped at the door. 'Come in,' said her mother's voice; and Katie, her face shining with joy, burst into the room. 'Mamma, mamma, I am a child of God! My sins are forgiven--Jesus is my Saviour!' she cried, flinging herself into her mother's arms. And this was the same Katie, who had been so shy and backward that she had never before dared to speak about her spiritual anxieties, even to her mother! Ah! what a change real conversion, or change of heart, had made. For the next six months Katie was so happy that she felt as if she were walking on air. 'I used to tremble,' she tells us, 'and even long to die, lest I should back-slide or lose the sense of God's favour.' But as time went on she learned, as we all have to do, to walk by faith, not by sight, and to serve and follow the Saviour whether she had happy feelings or not.