A good question which many ask. Some people see religion as the cause of discord and disrespect, and believe that humanity would be better off without it. However, if people truly followed the teachings of their religions, then they would live in harmony and have respect for one another. This idea is often called "The Golden Rule".
"...you shall love your neighbour as a man like yourself."
"What is hateful to you, do not to your fellow man. This is the law: all the rest is commentary."
"Always treat others as you would like them to treat you: that is the Law and the Prophets."
"None of you [truly] believes until he wishes for his brother what he wishes for himself."
"This is the sum of duty: do not do to others what would cause pain if done to you."
"Hurt not others in ways that you yourself would find hurtful."
"The minds of all are like precious jewels; to harm them is not good at all."
"Recognise there is only one race, and that is of all humanity."