There seems to be a widespread belief among Muslims that black magic only affects sinners. This is not true. Black magic can affect anyone. I have personally seen some very religious people being affected by black magic. Even Tablighees get affected by black magic. If a Tablighee and his family members can get affected, anyone can get affected.
If black magic only affected sinners, the first people to have been affected would have been politicians, murderers, rapists etc.
Some people go to black magic victims and tell them to do astaghfar because the magic could have been a result of his/her sins. The only people who need to do astaghfar are those who suggest it to black magic victims.
It is true that a religious person will be able to keep the effects of magic under control whereas it will affect a non religious person more, but black magic will affect both, and create misery in both people’s lives.
Prophet Mohammad (S.A.W.) was also affected by black magic. So much for black magic only affects sinners.