Terrorist groups are not solving problems of the world - they are the problem by themselves. The leaders from these groups are nothing else than cowards which likes to empower themselves by hiding them behind some "religious scripts" for building up their own religious dictatorship. So why you should give your life for such idiots? You have only one life! Life is not a video game, which can get started over again and again. Do you like to give your life for cowards by killing innocent people?
No "hero", but a criminal career is waiting
Participation in a terrorist organization does not solve complex political problems. Thousands of people - religious minorities as well as Muslims - suffer from terrorist regimes like the IS, Boku Harum, Abu Sayyaf, etc.
Extreme brutality also against "own" people
It is already known that any insubordination against the Commander of the extremists in Syria or the Iraq as a betrayal is handled and sometimes immediately will be punished with death.
Loss of humanity
Anyone who is a victim of the radical rat catcher can easily end up as a murderer, a rapist and a robber. How can these crimes ever be reconciled with one's own conscience when this once awakens again?
Destroying one's own future
Radicalization can have criminal consequences. Whoever has decided to go the path of violence and become guilty, the return to a regular everyday life is almost impossible.
No ticket to paradise
Even from the Islamic point of view, crime can not be justified. Whoever thinks of attaining a high position in the hereafter on this way, is seized by a following fallacy. Every alleged leader who promises paradise for this or that act commits a presumptuous blasphemy.
War is not an action movie
What affects some people become so cool like a real computer game, is leg-harsh reality. Whoever gets into it, is not only playing with his own life and anyone else's, but also playing with his soul. As for violence everyone gets made responsible for his deeds at the latest in the hereafter.
For girls it is not the return to the somewhat transfigured early days of the Muslims, but the cruel reality of sexual exploitation. They are married to jihadists and passed on to the next one at their death. It must be clear to them that their men have cruelly killed people when they go to bed with them and see women of the "enemy" as religious and ethnic minorities as "prey" who can rape them.