Descendents of Adam and Eve are cursed with the sin of the original humans even though the descendents were not yet born when Adam and Eve allegedly ate the fruit. Thus the descendents, including us, are obviously not responsible for the transgression.
	Every fetus, newborn, infant, and child in the world was said to have drowned during the great flood of Noah because of the beliefs and religious practices of their parents and other adults.
	All of the members of a soldier's family were killed in retaliation for a sin committed by the father.

Examples are also seen in the Christian Scriptures (New Testament). Perhaps the most obvious case was the transfer of immense levels of sin from every human onto Jesus, who is frequently regarded by Christians as having led a sinless life. The sin potentially came from everyone who were alive at the time of Jesus, and who were alive before his ara, and who lived since his time.

Although transfer of sin from the guilty to the innocent is considered profoundly immoral by most ethical systems, it is fully integrated into Christian beliefs.

One result is a commonly held belief that if a person commits a crime, it is OK to retaliate against an entire community who share some factor with the perpetrator. The common factor might be religion, skin color, race, gender, nationality, sexual orientation, gender identity, etc. One of the most remarkable example of this concept of collective punishment occurred when President G.W. Bush ordered the invasion of Iraq in retaliation for the 9/11 terrorists who were mostly from Saudi Arabia. The common factor that linked the terrorists and the Iraqis was the religion of Islam. Another example was a Sikh who was murdered in the U.S. after 9/11 because his head covering was mistaken to be Muslim. A Hindu temple was attacked in Toronto shortly after 9/11 apparently because it was mistaken for a Islamic mosque.

	Top-down religions are based on revelations by a god to humanity, often through prophets. Typically, the revelation contains a creation story in which their god creates humans.
	Bottom-up religions involve humans struggling to understand the nature and expectations of their god. Their god(s) and/or goddess(es) are created by humans.

Many, perhaps most, people regard their own religion as the only top-down faith in existence. Being revealed by God, it must be true. The holy book either is god's word or contains god's word. All of the other religions in the world are seen as bottom-up faiths, and are thus severely limited by cultural factors, lack of knowledge of the social and natural sciences, tribal beliefs, etc. Given that their own religion is the only one revealed by God and that they know the fullness of truth, some find it difficult to tolerate other religions who only have part of the truth. More info.
 

The existence of Hell: Most monotheistic religions have historically taught that God will judge people after death and send them either to Heaven or Hell. Many, perhaps most, people believe that they and most of their fellow believers will end up in Heaven, while most or all followers of other religions will go to Hell. Similarly, many fundamentalist and other evangelical Christians believe that in the near future, during the Rapture, Christians who had been saved will rise through the air to meet Jesus Christ in the sky. The unsaved will remain on earth to experience a mass slaughter -- the largest genocide the world will have ever seen -- during the Tribulation and War of Armageddon. God is seen primarily as a wrathful deity who has such a low opinion of followers of other religions that he will organize a massive genocide on Earth, and later have their followers tortured for all eternity without hope of mercy or relief in Hell.

If God hates followers of other religions so intensely, then it may well be difficult for true believers to avoid denigrating and oppressing them.