SQL查找相关文本框

I'm having problems with finding similar text in a SQL column. I want to match up similar text in the BODY column from a user with other user's text in the BODY column. The MYSQL error says the subquery returns multiple rows but I'm not sure why that would be an issue. Please see the jSON link to see what I'm talking about. Please let me know if you need any more information from me.

JSON: http://shipstudent.com/complaint_desk/centralwall.php

MySQL:

SELECT profile_picture, body, post_date, filename, username FROM Posts, Users WHERE Posts.IDUser = Users.IDUser AND Posts.body LIKE (SELECT Posts.body FROM Posts WHERE Posts.IDUser = (SELECT Users.IDUser FROM Users WHERE Users.username = "noah")) ORDER BY `Posts`.`post_date` DESC;