When I’m trying to memorize a passage, short or long, I find it helpful to write down the first letter of each word of the passage. If it’s a long passage without paragraphs, I break it up into smaller sections. Then I begin by memorizing the last sentence of the last section, using the first letters of the words as cues if I stumble. When I can say that, then I work on the next to last sentence, following with the last sentence, and I work all the way through the passage from back to front. That way, I am making it easiest on my brain by saying the newest sentence first, and repetition has already helped me in remembering the other sentences.