Where exactly does Christ teach the "Golden Rule."
Most probably referencing Matthew 7:12 which says:
"Therefore all things whatsoever ye would that men should do to you, do ye even so to them: for this is the law of the prophets.
What is also interesting is Christ's follow up versus: 13-15:
Enter in at the straight gate: for wide is the gate, and broad is the way, that leadeth to destruction, and many there be which go in thereat:
Because straight is the gate, and narrow is the way, which leadeth unto life, and few there be that find it.
Beware of false prophets, which come to you in sheep's clothing, but inwardly they are ravening wolves.