It is narrated from Sayyiduna Jabir bin Abdullah (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: "Do not ask the People of the Book about anything (of the religion), for they will never be able to guide you, since they themselves have gone astray."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 2238