What are the teachings of Islam regarding the treatment of non-Muslims, and how can one respond to those who claim that Islam commands the killing of non-Muslims?

Jihad in Islam aims to liberate people from the worship of servants to the worship of God alone, from the narrowness of this world to its vastness, and from the injustice of religions to the justice of Islam. Legitimate fighting is for the exaltation of the word of God, and those who hinder this are fought. However, women, children, the elderly, monks, and the sick are exempt from fighting, unless they participate in the fighting by word or deed. Fighting in Islam is sanctioned to repel fitnah, which is worse than killing. Wars are a natural human phenomenon for retribution, and Muslims were not part of the world wars and other atrocities. Islam calls for repelling injustice and supporting the oppressed, as in the Almighty's saying: (Those who were expelled from their homes without right, except that they say, "Our Lord is Allah." And were it not that Allah checks the people, some by means of others, there would have been demolished monasteries, churches, synagogues, and mosques in which the name of Allah is much mentioned. And Allah will surely support those who support Him. Indeed, Allah is Powerful and Exalted in Might.)