Therefore all things whatsoever ye would that men should do to you, do ye even so to them: for this is the law and the prophets.
When Jesus taught what is now called the Golden Rule (Matthew 7:12), He was instructing His disciples to do unto others what they wanted done to them, He was not instructing unbelievers. I certainly do not want a person who believes in cannabalism of anyone over 30 to do unto me what he believes. The same came can be said of many other peoples.
Many have made claims that what Jesus said is merely a rehashing of what is found in other religions but this is untrue. Jesus' teaching is positive, it tells what a beleiver should do. The other religions' teachings are negative, they tell you what not to do.
The HINDU religion taught:
The MahabharataThis is the sum of duty: do naught to others which if done to thee would cause thee pain.
The BUDDHIST religion taught:
The Udana-VargaHurt not others with that which pains yourself.
The JEWISH traditions taught:
The TalmudWhat is hateful to you, do not to your fellow men. That is the entire Law; all the rest is commentary.
The BAHA'I faith teaches:
He should not wish for others that which he doth not wish for himself, nor promise that which he doth not fulfill.
Do you believe the Golden Rule applies to everyone? Should it?