Two are better than one. In mundane matters, in the study of Torah, and in the performance of mitzvot, it is advantageous to have a good friend who can provide assistance when needed.

Rabbi Yohanan said to his outstanding disciples: Go out and see which is the right path to which a person should adhere...Rabbi Yehoshua says: A good friend.

Yehoshua ben Perahya would say: Get yourself a teacher, and acquire a friend for yourself.

And acquire a friend for yourself; how so? This teaches that a person should acquire a friend for himself, and he can eat with him, drink with him, study the written Torah with him, study the Oral Law with him, reside with him, and reveal all his secrets to him – both Torah esoterica and his secret thoughts on worldly matters. For when they sit and engage in Torah together, and one of them errs in understanding a halakha or subject matter, or if he says about ritual impurity that it is pure, or about ritual purity that it is impure, his friend can correct him. From where is it derived that when his friend corrects him and studies the written Torah with him they receive a better reward for their efforts? As it is stated: “Two are better than one, because they have a better reward for their toil” (Ecclesiastes 4:9).

If you have friends, some who reprove you and some who praise you, love those who reprove you and hate those who praise you, because those who reprove you will bring you to life in the World to Come, and those who praise you remove you from that world.

“Worry in the heart of a man, he should suppress it [yash’hena]” (Proverbs 12:25). Rabbi Ami and Rabbi Asi disagree. One said: He should remove worry [yesihena] from his mind. And one said: He should tell [yesihena] others his worries.

Either friendship or death.

If you want a beloved friend to cleave to you, you should advocate for him. (Mishna Avot 2:9, 1:6; Avot deRabbi Natan, version A, chaps. 8, 29; Yoma 75a; Ta'anit 23a; Avot deRabbi Natan, version B, chap. 26)