Q. Which of the two have the most severe punishment, the one who is disobedient or the innovator?
A. The innovators have a more severe punishment. That is because innovation is more severe than disobedience. Innovation is more beloved to Shaytaan than the acts of disobedience. That is because the disobedient one repents, as for the innovator, it's rare that he repents. That is due to him thinking that he's upon the truth, different from the one who is disobedient. Indeed, the one who is disobedient knows he's disobedient and that he's committing an act of disobedience. As for the innovator he sees (himself) as being one who is obedient to Allaah. Based upon that, the innovation -and Allaah's refuge is sought from that- is more evil than the act of disobedience. Therefore, the Salaf used to warn against sitting with the deviants because they have a negative affect upon the one who sit with them and their evil is severe. There's no doubt that innovation is more evil than the acts of disobedience, and the danger of the innovator upon the people is more evil than the danger of the disobedient. Based upon this, the Salaf have said:
"Being moderate upon the Sunnah is better than striving hard upon innovation"
Sisters Upon Al-Istiqaamah