Flip open to the book of Romans to answer this question. Find Romans 5:7-8, "For scarcely for a righteous man will one die; yet perhaps for a good man someone would even dare to die. But God demonstrated His own love toward us, in that while we were still sinners, Christ died for us."
Okay. One more. Flip (or click) to the book of John, and look up John 15:13, "Greater love has no one than this, that he lay down his life for his friends."
There it is: Willingness to lay down your life for the person you call friend. That is the true Biblical definition of friendship. If you stop reading this article right now and walk away with that, you'll be left with more than enough to muse over for the rest of the day.
I know for me, reading and going through the Scriptures as I wrote this article, this high standard still blows me over. It is a standard that was set for us by Christ, His being a pure example of His laying down His life for us while we were still soaked in sin, before we even accepted Him as our Savior or even as our friend.
Now, it is highly unlikely that the day will come when you will need to decide who on your Facebook friends list you would be willing to lay your life down for. (Although I am mentally doing that exercise out of curiosity and going back to my mind being blown.) Proverbs is an excellent source of wisdom of how we can understand friendship better in daily life.
"A friend loves at all times, and a brother is born for adversity." —Proverbs 17:17 - Love is a choice, and true friendship is when we love that friend all the time, not just when it is convenient.
"A man of many companions may come to ruin, but there is a friend who sticks closer than a brother." —Proverbs 18:24 - There is nothing wrong with having acquaintances, but remember the friend in our Lord who is there for you all the time. He shouldn't be the last one you go to with your problems; make Him the first.
"Wounds from a friend can be trusted, but an enemy multiplies kisses." —Proverbs 27:6 - One of the greatest things about true Biblical friendship is knowing that when a friend says something to you about an area in which you need to grow, you know their intent is from love. If they didn't love you and value you, they wouldn't risk telling you something you didn't want to hear!
"As iron sharpens iron, so one man sharpens another." —Proverbs 27:17 - Friendship is built on mutual trust and respect, and you should be building each other up, not falsely or with empty words, but for the purpose of helping each other grow.
The true Biblical definition of friendship is laying down your life for another person (John 15:13; Romans 5:7-8). A true friend will not create conflicts and drama (Proverbs 17:17). A true friend will stay with you even when life is rough (Proverbs 18:24). A true friend will forgive you when you mess up (Proverbs 27:6). A true friend will help you become a better person (Proverbs 27:17).
Heidi Joelle spends her days staring at paperwork and making sure it is where it is supposed to be, how it is supposed to be, when it is supposed to be. And then she comes home and makes sure the porky little dog isn't eating a trashcan. Between these two events, she tries to learn and see as much of the world around her as possible.