Surah Aali Imran (The Family of Imran), Verse 20

فَاِنْ حَآجُّوْكَ فَقُلْ اَسْلَمْتُ وَجْهِیَ لِلّٰهِ وَمَنِ اتَّبَعَنِ وَقُلْ لِّلَّذِیْنَ اُوْتُوا الْكِتٰبَ وَالْاُمِّیّٖنَ ءَاَسْلَمْتُمْ فَاِنْ اَسْلَمُوْا فَقَدِ اهْتَدَوْا وَاِنْ تَوَلَّوْا فَاِنَّمَا عَلَیْكَ الْبَلٰغُ وَاللّٰهُ بَصِیْرٌ بِالْعِبَادِ 

Fa in haaajjooka faqul aslamtu wajhiya lillaahi wa manit taba'an; wa qul lillazeena ootul Kitaaba wal ummiyyeena 'a-aslamtum; fa in aslamoo faqadih tadaw wa in tawallaw fa innamaa 'alaikal balaagh; wallaahu baseerum bil 'ibaad

“So if they dispute with thee, say: "I have submitted My whole self to Allah and so have those who follow me." And say to the People of the Book and to those who are unlearned: "Do ye (also) submit yourselves?" If they do, they are in right guidance, but if they turn back, Thy duty is to convey the Message; and in Allah's sight are (all) His servants.”

Quran 3:20 (Yusuf Ali Translation)