Lisa Marie Presley is opening up about the heart-wrenching death of John Travolta and Kelly Preston's 16-year-old son, Jett.

In a message on her MySpace blog entitled "Now is Not The Time," Lisa Marie says her "heart is crying and bleeding" for the Travoltas after suffering such a loss to their family -- and she also encourages people not to use the tragedy as an opportunity to attack Scientology.

Here are portions from Lisa's blog entry:

"I wished I could be writing you under happier circumstances but I cannot because two of my very good friends, (John and Kelly Travolta ) the sweetest people in the world have just encountered the worst possible tragedy a parent could be forced to endure, the death of their son Jett.

My heart is crying and bleeding for them. I personally would not have it in me to bury my own child. I am writing this because I have noticed that for the most part, people and the media have been very sympathetic and respectful, but there are those certain ones that want to use this horrible tragedy as an opportunity to once again, blame and or attack Scientology?

Folks, as popular as it has been to discriminate and ridicule Scientology and Scientologist's in the recent past, Now is NOT the time."

Lisa goes on to write:

"Just like anyone else, If one is sick, they go to the doctor, If a medication will make it better then they take it. If they don't then they are an idiot and you can't blame their religion. Whatever medical and or physical condition Jett had , I can tell you first hand that his parents were on a tireless, never ending quest to get and provide him with the absolute best care anyone could ever ask for and need, Medically, physically, emotionally, medicinally and spiritually."