Do the rulings on polytheism that we apply in our world not apply throughout the entire universe, and are there places in the universe where the dead can hear and help the living, and is visiting graves a form of worship?

The Messenger of Allah, peace and blessings be upon him, warns us against the whispers of Satan and guides us to seek refuge in Allah and to cease these whispers. The Companions came complaining about the whispers they experienced, and the Messenger informed them that their aversion to such whispers is a clear sign of faith.

Satan only whispers to the people of faith, and the entire universe is managed and sustained by Allah alone.

To confront Satan, the following is recommended: 1. Adhering to the Qur'an and Sunnah, both in knowledge and practice, and avoiding the paths of misguidance. 2. Seeking refuge in Allah from all evils in specific situations, especially with Surahs Al-Falaq and An-Nas. 3. Engaging in remembrance (dhikr), for it is a fortress against Satan. 4. Adhering to the Muslim community and living in Muslim lands. 5. Opposing Satan in everything he commands or whispers, for he is not a sincere advisor. 6. Repentance and seeking forgiveness, for Allah forgives His servant as long as he seeks His forgiveness.

These means help in repelling the whispers of Satan.