Islam teaches and obliges Muslims to be honest and truthful to all around them regardless of their faith or race. It is therefore prohibited for a Muslim to lie when speaking to others, whether they are Muslims or non-Muslims. The Prophet (peace and blessings be upon him) is reported to have said, “Stick to truthfulness, for it leads one to righteousness, and the latter leads to Paradise. Thus, when one sticks to truthfulness and shows keenness in it, Allah considers him as an absolutely truthful man. And avoid telling lies, for it leads to excessiveness, and this leads to Hellfire. Thus, when one persists in telling lies, Allah considers him as a liar” (Al-Bukhari).
The Prophet (peace and blessings be upon him) is also reported to have considered one who lies when talking to others or when dealing with them to be a hypocrite. He (peace and blessings be upon him), “The hypocrite has three characteristics: he tells lies, breaks his promise, and breaches the trust” (Al-Bukhari and Muslim).
Dr. Muzammil Siddiqi, president of the Fiqh Council of North America, states the following: Islamic ethical rules are universal values that are not restricted to Muslims’ dealings with Muslims. Whatever is deemed unethical is forbidden to be practiced with Muslims or non-Muslims. And whatever Muslims are forbidden to do in Islam, they must refrain from whether they are dealing with Muslims or non-Muslims.
Lying, of course, is forbidden in Islam; therefore, the Muslim is prohibited to lie to anyone, Muslim or non-Muslim. The Prophet (peace and blessings be upon him) is reported to have said, “And avoid telling lies, for it leads to excessiveness, and this leads to Hellfire. Thus, when one persists in telling lies, Allah considers him as a liar” (Al-Bukhari).