Surah An-Nisa' (The Women), Verse 171

یٰۤاَهْلَ الْكِتٰبِ لَا تَغْلُوْا فِیْ دِیْنِكُمْ وَلَا تَقُوْلُوْا عَلَی اللّٰهِ اِلَّا الْحَقَّ اِنَّمَا الْمَسِیْحُ عِیْسَی ابْنُ مَرْیَمَ رَسُوْلُ اللّٰهِ وَكَلِمَتُهٗ اَلْقٰىهَاۤ اِلٰی مَرْیَمَ وَرُوْحٌ مِّنْهُ فَاٰمِنُوْا بِاللّٰهِ وَرُسُلِهٖ وَلَا تَقُوْلُوْا ثَلٰثَةٌ اِنْتَهُوْا خَیْرًا لَّكُمْ اِنَّمَا اللّٰهُ اِلٰهٌ وَّاحِدٌ سُبْحٰنَهٗۤ اَنْ یَّكُوْنَ لَهٗ وَلَدٌ لَهٗ مَا فِی السَّمٰوٰتِ وَمَا فِی الْاَرْضِ وَكَفٰی بِاللّٰهِ وَكِیْلًا 

Yaaa Ahlal Kitaabi laa taghloo fee deenikum wa laa taqooloo 'alal laahi illalhaqq; innamal Maseehu 'Eesab-nu-Maryama Rasoolul laahi wa Kalimatuhooo alqaahaaa ilaa Maryama wa roohum minhum fa aaminoo billaahi wa Rusulihee wa laa taqooloo salaasah; intahoo khairallakum; innamal laahu Ilaahunw Waahid, Subhaanahooo any yakoona lahoo walad; lahoo maa fissamaawaati wa maa fil ard; wa kafaa billaahi Wakeelaa

“O People of the Book! Commit no excesses in your religion: Nor say of Allah aught but the truth. Christ Jesus the son of Mary was (no more than) a messenger of Allah, and His Word, which He bestowed on Mary, and a spirit proceeding from Him: so believe in Allah and His messengers. Say not "Trinity": desist: it will be better for you: for Allah is one Allah: Glory be to Him: (far exalted is He) above having a son. To Him belong all things in the heavens and on earth. And enough is Allah as a Disposer of affairs.”

Quran 4:171 (Yusuf Ali Translation)