Young man, be aware of these four good-hearted friends: the helper, the friend who endures in good times and bad, the mentor, and the compassionate friend.
The helper : can be identified by four things: by protecting you when you are vulnerable, and likewise your wealth, being a refuge when you are afraid, and in various tasks providing double what is requested.
The enduring friend : can be identified by four things: by telling you secrets, guarding your own secrets closely, not abandoning you in misfortune, and even dying for you.
The mentor : can be identified by four things: by restraining you from wrongdoing, guiding you towards good actions, telling you what you ought to know, and showing you the path to samsaric heavens.
The compassionate friend : can be identified by four things: by not rejoicing in your misfortune, delighting in your good fortune, preventing others from speaking ill of you, and encouraging others who praise your good qualities.
- Taken from the Sigalovada Sutta