An innovation in religion that is not in harmony with it is rejected

Messenger of Allah ﷺ said, "If somebody innovates something which is not in harmony with the principles of our religion, that thing is rejected."  

قَالَ رَسُولُ اللَّهِ ﷺ: «مَنْ أَحْدَثَ فِي أَمْرِنَا هَذَا مَا لَيْسَ فِيهِ فَهُوَ رَدٌّ۔»