"I heard the Messenger of Allah say: 'Whoever revives a Sunnah of mine that dies out after I am gone, he will have a reward equivalent to that of those among the people who act upon it, without that detracting from their reward in the slightest. Whoever introduces an innovation (Bid'ah) with which Allah and his Messenger are not pleased, he will have a (burden of) sin equivalent to that of those among the people who act upon it, without that detracting from their sins in the slightest.'" (Using translation from Ibn Mājah 210)
"اعْلَمْ يا بلالُ أَنَّهُ من أحيا سُنَّةً من سُنَّتِي قد أُمِيتَتْ بعدى كان له من الأَجْرِ مثلُ من عمل بها من غيرِ أن يَنْقُصَ من أُجُورِهم شيئًا، ومن ابتدعَ بدعةَ ضَلالةٍ، لا يَرْضَاهَا اللهُ ورسولُه كان عليه مثلُ آثام من عمِل بها، لا ينقُصُ ذلك من أَوزَارِ الناس شيئًا" .