He is an atheist currently and is here to study Islam not Christianity. In Islam our sources are the Holy Qur'an, authenthic Hadith, Ijma' and Qias of the ulama. From where did you bring the bible as one of the source to study Islam? I don't want to hijack this thread hence I don't want to say more.
Easy hard rock, all I said was that reading the Holy Qur'an becomes a bit easier after you have read the Holy Bible because one would recognise the Prophets and their situations as mentioned in the Holy Qur'an. For example, in the Holy Qur'an Prophet Musa (pbuh) is mentioned a few times, and on reading the Holy Bible one would become familiar with Prophet Musa (pbuh) and his exodus from Egypt and the pharoah if one reads the Holy Bible. There is no harm in reading the Holy Bible as long as one understands that it has been corrupted.