中国没有这句常用语，不是完整的句子。

The host should be hospital to the guest and the guest should be respectful to the host. This is a decorum on how people behave should towards each other in ancient times among various races. Even in the Bible, the daughters of Lot are to be sacrificed to the mob to ensure the safety and dignity of his guests. Here the "guest" does not mean a patron to an establishment but a welcomed stranger to the house.

I think it might be interpreted as 'I help others while others help me'. Or it may be simply put it as 'all the people help each other'.

中文的原文“我为人人，人人为我”，这句话是说所有人之间的关系。改成“我为客人，客人为我”，好像主人和客人的关系不一定是这样吧？有点逻辑上讲不通 权当我是开饭馆的，我做的工作就是为了来吃饭的客人吗？不是，我还为了我的家人、我的亲戚朋友、我的领导同事等等，客人只是我为了的一部分，顶多是主要的部分，怎么能说“我为客人，客人为我”呢？难道离了我客人就吃不上饭了吗？客人完全可以另外找个饭馆子吃饭。