Proverbs 17:17 (NKJV)
A friend loves at all times, And a brother is born for adversity.
1 Samuel 18:1-4 (NKJV)
Now when he had finished speaking to Saul, the soul of Jonathan was knit to the soul of David and Jonathan loved him as his own soul.
Saul took him that day, and would not let him go home to his father's house anymore.
Then Jonathan and David made a covenant, because he loved him as his own soul.
And Jonathan took of the robe that was on him and gave it to David, with his armor, even to his sword and his bow and his belt.
1 Samuel 20:1-4 (NKJV)
Then David fled from Naioth in Raham, and went and said to Jonathan, "What have I done? Was it my iniquity, and what is my sin before your father that he seeks my life?".
So Jonathan said to him, "By no means? You shall not die! Indeed, my father will do nothing either great or small without first telling me. And why should my father hide this from me? It is not so!"
Then David took an oath again, and said, "Your father certainly knows that I have found favor in your eyes, and he has said "Do not let Jonathan know this, lest he be grieved.' But truly, as the Lord lives and as your soul lives, there is not a step between me and death."
So Jonathain said to David, "Whatever you yourself desire, I will do it for you."
1 Samuel 20:42 (NKJV)
Then Jonathan said to David, "Go in peace, since we have both sworn in the name of the Lord, saying, 'May the Lord be between you and me, and between your descendants and my descendants, forever'" So he arose and departed, and Jonathan went into the city.
John 15:12-17 (NKJV)
"This is My commandment, that you love one another as I have loved you.
Greater love has no one that this, than to lay down one's life for his friends.
"You are My friends if you do whatever I command you.
No longer do I call you servants for a servant does not know what his master is doing; but I have called you friends, for all things that I heard from My Father I have made known to you.
You did not choose Me, but I chose you and appointed you that you should go and bear fruit, and that your fruit should remain, that whatever you ask the Father in My name He may give you.
These things I command you, that you love one another.
Ecclesiastes 4:8-12 (NKJV)
There is one alone, without companion: He has neither son nor brother, Yet there is no end to all his labors, Nor is his eye satified with riches. But he never asks, "For whom do I toil and deprive myself of good?" This also is vanity and a grave misfortune.
Two are better than one, Because they have a good reward for their labor.
For if they fall, one will lift up his companion. But woe to him who is alone when he falls, For he has no one to help him up.
Again, if two lie down together, they will keep warm; But how can one be warm alone?
Though one may be overpowered by another, two can withstand him. And a threeford cord is not quickly broken.