Is it permissible for me to give to Christians books which contain aayaat of the Qur’aan that prove the Oneness of Allaah, which are written in Arabic with the translation of the meaning written in English?

Praise be to Allaah.
Yes, it is permissible for you to give them books containing aayaat from the Qur’aan and to use (these quotations) to prove various issues, Tawheed and others, whether this is in Arabic or the meanings are translated. This is a deed for which you are to be commended, because giving them or lending them to them is a kind of conveying the message and calling them to Allaah (da’wah). The one who does this will be rewarded if his intention is sincere.

From Fataawaa al-Lajnah al-Daa’imah, 12/251