Whoever calls to guidance shall receive a reward similar to these obtained by those who follow him without that diminishing anything from their rewards. and whoever calls to misguidance shall incur a sin similar to these incurred by those who follow him without that diminishing anything from their sins. [Müslim]

عن أبي هريرة رضي الله عنه مرفوعًا: «مَن دَعَا إلى هُدى، كَان لَه مِنَ الأَجر مِثل أُجُور مَن تَبِعَه، لاَ يَنقُصُ ذلك مِن أُجُورِهِم شَيئًا، ومَنْ دَعَا إلى ضَلاَلَة، كان عَلَيه مِن الإِثْم مِثل آثَامِ مَن تَبِعَه، لاَ يَنقُصُ ذلك مِن آثَامِهِم شَيْئًا». [صحيح.] - [رواه مسلم.]