Sunan Ibn Majah Book 0, Hadith 205

حَدَّثَنَا عِيسَى بْنُ حَمَّادٍ الْمِصْرِيُّ، أَنْبَأَنَا اللَّيْثُ بْنُ سَعْدٍ، عَنْ يَزِيدَ بْنِ أَبِي حَبِيبٍ، عَنْ سَعْدِ بْنِ سِنَانٍ، عَنْ أَنَسِ بْنِ مَالِكٍ، عَنْ رَسُولِ اللَّهِ ـ صلى الله عليه وسلم ـ أَنَّهُ قَالَ ‏ "‏ أَيُّمَا دَاعٍ دَعَا إِلَى ضَلاَلَةٍ فَاتُّبِعَ فَإِنَّ لَهُ مِثْلَ أَوْزَارِ مَنِ اتَّبَعَهُ وَلاَ يَنْقُصُ مِنْ أَوْزَارِهِمْ شَيْئًا وَأَيُّمَا دَاعٍ دَعَا إِلَى هُدًى فَاتُّبِعَ فَإِنَّ لَهُ مِثْلَ أُجُورِ مَنِ اتَّبَعَهُ وَلاَ يَنْقُصُ مِنْ أُجُورِهِمْ شَيْئًا ‏"‏ ‏.‏

It was narrated from Anas bin Malik that:The Messenger of Allah said: "Every caller who invites people to misguidance and is followed, will have a burden of sin equal to that of those who follow him, without that detracting from their burden in the slightest. And every caller who invites people to true guidance and is followed, will have a reward equal to that of those who follow him, without that detracting from their reward in the slightest