Good friends are like angels. You don't have to see them to know they are there for you.

Friendship is as great as a True Friend
And a True Friend is as great as Friendship.

A bartender's true friend only drinks coffee

A friend is like a mirror: he’s the one who reflects your light most accurately. However, a close friend not only reflects your self but enhances and embellishes it.

No better relation than a prudent and faithful Friend

A best friend should be a true friend and a true friend should be the best friend.