“Make someone your Rebbie and acquire a friend” — Yehoshua ben Perachia (Avot 1:1)
A man needs a good friend for three purposes:
1) To learn Torah. As one Sage said: “I have learned much from my teachers, but even more from my friends.”
2) To be more careful in observing the mitzvot. Even if one of them will be tempted to transgress he will not allow the other to fall as well.This offers hope for both of them to improve.
3) To enjoy his counsel and have someone in whom he can confide.
The term “acquire” employed here is to indicate that if he can find no other route he should be prepared to pay anything to gain a good friend. It also suggests that one should be prepared to “buy” a good friend with soft-spoken patience and to show him tolerance, even when he says something offensive. Otherwise the differences in human personalities will create situations that will lead to strains that can endanger the friendship.