Cardinal rule of being a messiah, is being vague enough that your message can be totally misconstrued. It really doesn't matter what your message is, as long as people can contort it to fit their desires. Keep in mind however, that people as a rule do not want to be totally happy. They wallow in their guilt, their shame, their depression. As long as you feed them something to fuel their guilt, they'll ignore the rest of your message and focus on their self constructed depravity.
Keep in mind however, that as a messiah your good intentions(if it's possible for one to cause so much suffering with good intentions) will be the cause of wars for millenia following your death. which will be painful and early in life, due to people being unable to cope with the parts of your message they disagree with. the sooner you are dead, the sooner they can begin to misinterpret it.