Question

what does "By a name I know not how to tell thee who I am. My name, dear saint, is hateful to myself because it is an enemy to thee. Had I it written, I would tear the word." mean

Answer 1

The author of that is saying that he/she can't tell the person they're writing to what their name is because it will make the person realize that they're an enemy, and if the author had written his/her name s/he would've torn it out