What is "door gods"
The door god, the god of the guards of the gate, is a type of painting that is pasted on the door on the Lunar New Year. As the deity guarding the portal of folk belief, people paste its statue on the door to ward off evil spirits, guard the family house, ensure peace, help utilitarianism, and descend auspiciousness, etc. According to traditional customs, on the eve of the Spring Festival, every household would paste couplets and door gods to pray for the coming year.
The door gods should be posted on both sides of the door. The traditional method of posting the door gods face-to-face is considered correct, while the back-to-back way is incorrect.
The origins of "door gods"
It is said that after Li Shiming, the king of the Tang Dynasty,
ascended the throne and became emperor through the Xuanwu Gate Incident, he often had nightmares for some time. He dreamed that his brother and younger brother were coming to kill him with demons and ghosts. He was very afraid and could not sleep at night. So he asked two of his senior generals, Qin Shubao and Yuchi Gong, to stand guard in front of the gate with weapons, so that he could sleep at ease. But because the two generals couldn't sleep for a long time， they all failed ill in the end. So Li Shiming had to order someone to draw their images on paper and stick them on the door to deter monsters, which was the origin of the door god.
Legend has it that in ancient times, there was a mountain called Dushuo Mountain in the East China Sea. The scenery on the mountain was beautiful, and there was a large peach tree winding for three thousand miles. There lived a golden rooster on the tree, and every day at dawn, the golden rooster stood at the top of the tree and crowed. The crow spread throughout the land, and the roosters all over the world would also crow. At this time, the sun would rise from the east, bringing light to all living beings, At this moment, when the demons and ghosts in the world heard the rooster crowing, they knew they could no longer wander outside. But these ghosts didn't want to go back every day, so they discussed going to the Mountain to destroy this peach tree. After the Emperor of Heaven discovered it, he sent two gods, Shentu and Yulei, to subdue these demons and ghosts. These ghosts and monsters were afraid of Shentu and Yulei and had to obediently behave themselves. Later, the common people learned that ghosts and monsters were afraid of the two heavenly gods and hence carved portraits of the two heavenly gods on peach boards and placed them at the entrance to deter the ghosts. Gradually, Shentu and Yulei became the folk door gods.