In his Life of Catherine of Siena, Bl. Raymond of Capua records what St. Catherine had often told him Christ taught her when He first began appearing to her:
"Do you know, daughter, who you are and who I am? If you know these two things you have beatitude in your grasp. You are she who is not, and I AM HE WHO IS. Let your soul but become penetrated with this truth, and the Enemy can never lead you astray; you will never be caught in any snare of his, nor ever transgress any commandment of mine; you will have set your feet on the royal road which leads to the fulness of grace, and truth, and light."