Sayyiduna Mu'adh bin Jabal (may Allah be pleased with him) said that the Messenger of Allah (peace and blessings be upon him) said: "What I fear most for my Ummah are three: a man who reads the Book of Allah until, when you see its splendour upon him, and he is wearing the garment of Islam - which Allah has lent him - he draws his sword, strikes his neighbour with it, and accuses him of shirk." It was asked: O Messenger of Allah, which of them is more deserving of it, the accuser or the accused? He (peace and blessings be upon him) said: "The accuser. And a man to whom Allah has given authority, and he says: 'Whoever obeys me has obeyed Allah, and whoever disobeys me has disobeyed Allah' - and he has lied; it is not for any caliph to be a shield in place of the Creator. And a man whom stories have made frivolous; whenever he finishes one tale, he narrates one longer than it. If he lives to meet the Dajjal, he will follow him."
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 17305