Christianity is approved by your Allah unless of course there is Contradictions in the Quran you wish to show otherwise!
2:62. Lo! Those who believe (in that which is revealed unto thee, Muhammad), and those who are Jews, and Christians, and Sabaeans - whoever believeth in God and the Last Day and doeth right - surely their reward is with their Lord, and there shall no fear come upon them neither shall they grieve.
Pickthal's Quran Translation
2:62. Those who believe (in the Qur'an), and those who follow the Jewish (scriptures), and the Christians and the Sabians,- any who believe in God and the Last Day, and work righteousness, shall have their reward with their Lord; on them shall be no fear, nor shall they grieve.
Yusuf Ali's Quran Translation
Contradiction Con`tra*dic"tion (?), n. [L. contradictio answer, objection: cf. F. contradiction.]
1. An assertion of the contrary to what has been said or affirmed; denial of the truth of a statement or assertion; contrary declaration; gainsaying. His fair demands Shall be accomplished without contradiction.
2. Direct opposition or repugnancy; inconsistency; incongruity or contrariety; one who, or that which, is inconsistent.