سورة Al-Imran ( The Famiy of Imran ) - الآية 20

Then if they argue with you, (O dear Prophet Mohammed – peace and blessings be upon him) say, “I have submitted my face (self) to Allah and likewise have my followers”; and say to the People given the Book(s) and the illiterate, “Have you submitted (accepted Islam)?” If they submit, they have attained the right path – and if they turn away (reject), then your duty is only to convey this command; and Allah is seeing the bondmen.