Peter Kassig, US citizens who became the target of the fifth beheading by ISIS (CNN)

Washington DC - The figure of Peter Kassig raised by ISIS in the fourth beheading video on foreigners. Converts who now named Abdul-Rahmah Kassig are hostages ISIS and subsequent execution is referred to as a target.

Seeing the situation, Peter's parents, Ed and Paula Kassig really down in the mouth. He also released a letter that was sent from the nest ISIS Peter.

"In order for people to know how great expectations and our attention to him (Peter)," said Ed and Paula, as published by the BBC on Monday (10/06/2014).

According to his parents, Peter previously worked as a volunteer for an organization that he founded in the Middle East. He was later arrested ISIS in Deir Ezzor, Syria, in 2013 ago.

Said his father and mother, Peter had converted to Islam before he was arrested. They said, Peter embraced Islam sincerely without any coercion from any party, after he learned to know the religion of his friend.

In his letter, Peter is a former United States Army, Army Ranger, said that he was very frightened. Fear of dying in bondage group ISIS.

Here's the letter Peter aka Abdul-Rahmah more.

"I was scared, scared to death and I like to lose hope, but I still have hope," said Peter in his letter.

"I am very sad to why this could happen. And for all of you who can not go home."

"If I die, I should be able to imagine the convenience when I went as a result of my hard work and help relieve those in need."

"In terms of my confidence, I pray every day, and I was not upset over the situation that I experienced today. Remain calm and patient."

"I love you," said Peter received a letter on June 2, 2014.

Previous ISIS has executed three foreigners. Two of them are journalists United States (USA) James Foley and Steven Sotloff. The other one is a British humanitarian worker David Haines.

ISIS recently executed a fourth victim, namely Alan Henning, a Briton who became volunteers for peace in the Middle East.