Love is one of the basic emotions, described as an extreme affection for a person, an object, an idea, a country, a friend or a family member. Love is used to describe affection for many different things, but can sometimes be misinterpreted for Lust.
Many faiths, such as Christianity, Judaism, Buddhism, etc., believe love to be a positive trait, and the followers of these religions are asked to practice love for others as a general principle for a good life.
The Five Grecian Forms
The ancient Greeks identified four forms of positive love:
- Philos - the love of close friends or brothers. Aristotle identifies several types of philos  which can include utility as well as shared characteristics and values. The word is often attached to groups of people who share a love of a common pursuit.
- Storge - the love of family. This would include patriotism - the love of country or homeland. Storge was a word used by the Greeks to describe a strong love that protects and makes secure.
- Eros - carnal or sexual love. This would include romantic love but would also include lust. Eros is intended by God, as laid down in the Bible, to be enjoyed between a married man and woman. The Greek word epithumia spoke of desire that found its fulfillment in sexual love.
- Agape - love which seeks the highest good of others, not just friends, family or brothers, but including enemies. This is considered by all major world religions to be the highest kind of love, although Buddhism would regard it as compassion. Agape is most often used to speak of God's love and in the days of biblical times it described love in its most profound and pure form. Apostle Paul chose the word agape for his description of love in 1.Corinthians 13.
The fifth form of love is called Narcissism, or self love. This word comes from the Greek myth of Narcissus, who fell in love with his own reflection. Although Freud considered that everybody has some degree of narcissism, and that this is present in us from birth,  if taken to extremes narcissism can be considered a personality disorder. 
The bible mentions love, especially Agape, repeatedly.
For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life.
Know therefore that the LORD your God is God; he is the faithful God, keeping his covenant of love to a thousand generations of those who love him and keep his commands.
I love those who love me, and those who seek me find me.
Atheism and its inability to explain love
See also: Atheism and love
- Aristotle, Nicomachean Ethics, Book VIII
- Thomas Nelson. David Sper:What Is Real Love?. RBC Ministries.
- Matthew 5:44
- Freud, Sigmund, On Narcissism: An Introduction, 1914
- Bible Verses on Love - God’s Love For Us. AllAboutGOD.com.
- How do atheists define love?
- What is love? how materialist atheism fails to have a satisfactory answer, July 9, 2014