It is narrated from Sayyiduna Uqbah bin Amir (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "What I fear most for my Ummah is the Book (the Qur'an) and milk. As for milk, it will be opened up for some people, so they will abandon the Friday and the Friday prayers; and as for the Qur'an, it will be opened up for some people (that is, they will learn to read it), so they will dispute with the believers by means of it."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 14887