The Greek word, "Agape", and it's corresponding verb form, "Agapao" are words that are translated "love" in the New Testament. A study of the words for love in Greek yields interesting results.
When the word love is used in English, one can mean he loves another person. One could say he loves his wife. One could say he loves his parents. One could say he is "in love". One could even say he loves apple pie. Each means something different. However, in biblical Greek, there are several different words for "love". We will look at only two.
Philea is a very common word for love in Greek. Words such as "Philadelphia" ("City of Brotherly Love") derive from this word. This word is used of those whom we hold in affection. Ordinary words for love (such as Philea) all have some emotional connotation behind them. However, they are not a virtuous love. One cannot help loving their own child or their spouse. "Falling in Love" is not an achievement, nor is it a virtue.
On the other hand, Agape demands the exercise of the whole person. Agape extends itself not only to the near and dear, but also to the unlovable. Agape does not require an emotional response. Agape is an achievement. It has to do with the mind, not just an emotion that wells up in our hearts and causes us to naturally feel affection.
By the world's standards, Agape is not natural. Who in their right mind loves their enemies? (Mt. 5:43ff). This "un-natural" kind of love is how people will know that we are Christians (Jn. 13:34-35). Agape is God's love (I Jn. 3:15-17; 4:8)
So, Agape is a love that says: "I love you regardless of what you do" - "I love you even if you don't love me" - "I love you because I choose to love you". We don't "fall" in love, we choose to love.
In I Corinthians 13, Paul describes it in no uncertain terms. Agape has been translated "charity" in some versions. If our relationships are based on this kind of love, a love not dependent on the other person but on our decision to love, then in Paul's words, "love never fails" (I Cor. 13:8).
Jesus instructed us to love one another. If we have his perfect, unconditional love, we will never fail. Now ask yourself, do I demonstrate love to my brethren?