In Water Margin, the first friend Lu made was Shi Jin. At that time, Shi Jin met Lu in a tea house in search of his master Wang Jin. Lu Zhishen always liked to make friends with heroes in the Jianghu. Seeing that Shi Jin was tall and burly like a tough guy, he immediately stepped forward to greet him. Later, he learned that this person was Shi Jin, a famous nine-dragon in the Jianghu, and asked him to go. From Lu Zhishen's performance, we know that his criteria for making friends are: first, being a hero; second, having a good reputation.

They met another person in the street, that is, Jong Li, Shi Jin's master. However, Jong Li doesn't look like a hero, but because he is Shi Jin's master, Lu Zhishen thinks he should be not bad, so he also invited him to have a drink together. However, I didn't expect that Jong Li was very secular, and he was reluctant to collect the food when he saw the guests. He lingered for a long time, only after selling a few ointments did he agree to go together, and when he rescued Jin Cuilian's father and daughter, < Thus, Lu's second criterion for making friends is generosity. When he fled to Taohua Mountain, he saw that Jong Li and Zhou Tong were not willing to use a lot of gold and silver in the shanzhai, and they had to rob him before seeing him off. Knowing that both of them were stingy, they left without saying goodbye.

Lu Zhishen is a martial arts practitioner, and he admires martial arts heroes. Therefore, when he saw Lin Chong's extraordinary skills, he immediately became sworn brothers with Lin Chong. Later, when he met Wu Song, the two became inseparable friends, which is also the reason. As for Lu Zhishen's association with a gang of gangsters while guarding the vegetable garden, it was just to pass the time when he was bored. They were not in the same class as Lu Zhishen at all, so they were not really Lu Zhishen.