Sayyiduna Ma'qil bin Yasar al-Muzani (may Allah be pleased with him) says that I heard him (peace and blessings be upon him) say: "Any man who becomes the guardian of (any) people and deceives them, and dies in that state, Allah has made Paradise forbidden for him."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب قتال أهل البغي / 16639