Today, Yonatan puts on Tefillin every day. But just a few years ago, under a different name, he would greet his friends by saying "Heil Hitler."
Like many others, Jonathan was indoctrinated into the extreme right when he was a teenager. When he was 14, he joined a karate group in Berlin which had a neo-Nazi coach.
"It's not that he sat down and said to himself I have here a child, let's make him a Nazi. He was just very sure of his way," Yonatan told Antonia Yamin, Chief Europe Correspondent of Kan 11 News. "In the karate group we had a lot of older people. People who were ten years older than me. We did a lot of things together but we also heard Nazi music in the training camp."
"Of course we talked about the war.," he explained. "For example, that it didn’t take much in order to conquer Poland and France. Or that it was a mistake not to attack England, or how the war could be won, or that it was so easy to conquer all of Europe."
Yonatan described how he was taught "you have to completely destroy the Jewish world domination."
One night, Yonatan had a dream in which the word 'Kabbalah' appeared. When he awoke, he began to research what his dream had been about and discovered the Kabbalah, the Jewish mysticism.
Yonatan began to study Kabbalah, and cut off contact with his old friends. At one point, he even flew to London to work at the local Kabbalah center.
"This of course was a time that helped me to recover. I could leave things behind, leave the city behind. I had new people, there were only positive people, good people who wanted the best for me,who wanted to help me and were patient with me."
Yonathan said that the light, love and optimism that surrounded him from all sides made him decide that he wanted to be a Jew. A year and a half ago he underwent an Orthodox conversion to Judaism.
In recent weeks Yonatan has decided that he has to complete the change. And in two months he plans to immigrate to Israel. His main hope is that the Israelis will forgive him for his past.