(Sorry for the grammar lesson but I think it may help.)
Homonyms (one of two or more words spelled and pronounced alike but different in meaning (such as “key” in the lock or the song is in the “key” of F) are different in every language. This is why every once in awhile we must examine the Greek and Hebrew languages as our study of the Bible gets deeper and deeper to understand the context and translation.
In English we have one word for “love” which we give many different meanings by adding a qualifying adjective. For instance, “romantic love” or “brotherly love” or “first love”. Greek has 3 distinct, separate words for different types of love, only 2 of which are found in the NT.
Eros is not found in the NT but refers to love for an adorable object, especially for love between a man and woman. Depending on the context we would translate this as “first love”, “romantic love”, etc. It’s akin to infatuation for a person (“I really love her/him.”) or a thing (“I love potato chips.”) This kind of love presumes that the object of the love is worthy of one’s love – the object’s value is relative. The beauty or worth of the object of love is in the eye of the beholder.
Phileo is the Greek word equating to friendship-love and is found frequently in the NT. From this word we’ve derived “Philadelphia”, meaning “brotherly love”. Phileo implies mutual affection and that the value or worth of the object of the love is relative; it’s in the eye of the beholder. (For instance, one criminal may have a close friendship with another criminal.) Phileo is used in some surprising places in the NT such as 1 Cor. 16:22, “If anyone does not love the Lord, he is to be accursed.” Two verses later in 16:24, however, Paul states, “My love be with you all in Christ Jesus.” using the next word for love: Agape.
Agape is frequently described as “unconditional love” (note the adjective). This is true but it means much more. Agape characterizes God. 1 John 4:8, “The one who does not love does not know God, for God is love.” It’s the love God manifested in the gift of His Son. John 3:16, “For God so loved the world, that He gave His only begotten Son, that whoever believes in Him shall not perish, but have eternal life.” It is much more than just mutual affection; it expresses unselfish caring for the object of love based on his or her intrinsic value. Meaning that the value of the person is not relative but that he or she has value in and of themselves. The value for each person is not supplied by man but by God.
Agape can also refer to a person or things. 1 John 2:15, “Do not love the world nor the things in the world. If anyone loves the world, the love of the Father is not in him.” When Scripture states, “God so loved the world,” it implies that the world (mankind) has an intrinsic value, that value being placed by God Himself. Therefore a quality of agape is it’s the kind of love that loves the unlovable. However, intrinsic value does NOT imply that the love is deserved. In fact, agape implies that the love is offered whether it is deserved or not, such as for our enemy. Matthew 5:44, “But I say to you, love your enemies….” Our enemies may not deserve agape but we are to offer it anyway because of the intrinsic value God has placed on them as an object of love.
The NT brings additional qualities to the Greek definition of agape by teaching that the love offered is so great that one is willing to lay down his life for the sake of the other person. John 15:13, “Greater love has no one than this, that one lay down his life for his friends.” Acting on this love that was first revealed from the Father (John 3:16), as disciples of Christ we are instructed in John 15:12, “This is My commandment, that you love one another, just as I have loved you.”
Finally, agape does not imply “without feeling”. It does not translate into an emotionless act based purely on obedience. It can carry very strong emotion with it. However, the essential nature of the word is that one offers agape whether they feel like it or not. Why? Because the object of the love carries more value than one’s personal feelings, needs, wants, desires or instincts. From this understanding we get the concept of “sacrificial love”. Therefore, by putting one’s negative feelings aside, love is given in the most difficult and even repugnant situations (e.g., a missionary’s work in India). Agape, as described in the NT is beyond human ability. It is the record of the life and earth of Jesus and the power of the Holy Spirit that enables the believer to love in such a manner.