Opposing Rasulullah şallAllāhu álayhi wa sallam command and changing şallAllāhu álayhi wa sallam sunna is misguidance and innovation. It is threatened by Allah with utter privation and punishment. Allah says:

Whoever splits from the Messenger şallAllāhu álayhi wa sallam after the guidance is clear to him and follows other than the path of the believers, We shall entrust him to what he has turned to and expose him unto Hell - an evil retreat! 

[Surah an-Nisa, Verse 115]

The Prophet şallAllāhu álayhi wa sallam said: 

Anyone who dislikes my Sunnah is not of me.

Narrated by Bukhari and Muslim.