“Young man ,know about this four best friends: the helper, the one who endures in good and bad times, the mentor and the compassionate one
The helper can be identified by four features: he will protect you and your wealth when you are vulnerable, he will protect you when you are afraid. He will also offer you more when you request something from him.
The four features of the enduring friend are , you will be able to tell your secrets to him and he will guard them with his life. He will even give his life to get you out of trouble and misfortune.
The mentor will restrain you from wrongdoing, he will guide you towards good actions, he will tell you what you must know, and he will always show you the path to the samsara heavens.
You can identify compassionate friend by these things. He will not rejoice your misfortune. He will always delight your good fortune. He will prevent others from speaking ill of you and always talk best about you with others.”
From the SIgalovada sutta