For example, in 1 Corinthians 13:13 in the King James Version reads, "And now abideth faith, hope, charity, these three; but the greatest of these is charity." That same verse in the very popular New International Version reads, "And now these three remain: faith, hope and love. But the greatest of these is love."
In all, the King James Version uses "charity" 29 times to translate the Greek word agape. On other occasions, however, that same version uses "love" to translate that same Greek word.
What's the difference between love and charity in the New Testament?
When the word agape is used in the context of vertical action (God toward man and/or man toward God), it is translated as "love."
When the word agape is used in the context of horizontal actions (man toward neighbor or enemy), it is translated as "charity."
It is certainly acceptable for modern translations to replace "charity" with "love," but I don't think it's preferable. The word "love," as we use it today, carries more than one meaning. We say we love ice cream. We say we love our family. We say we love our wives. We say we love God. We say we love music. You get the point.
Where we have one word, "love," the Greeks had four words:
agape was the word used to identify love that was selflessly committed to the well-being of another;
phileo was the word used for the non-sexual affection of those sharing a strong bond, like "brotherly love;"
eros was the word used for romantic feelings, like "being in love;"
storge was the word used for fondness of someone/something through familiarity with them/it.
(see The Four Loves by C.S. Lewis)
Besides the subtleties that are screened out when we use the word "love" in all those contexts, we have also developed a mental framework that equates love with abstract passivity. In other words, to a large degree, love has become a cerebral practice.
"Charity," on the other hand, captures the contours of concrete activity that are implied when agape is used in the context of horizontal (person to person) action. Of course, "charity," is not without its own cultural baggage - images of dropping coins in red containers at Christmas time come to mind. But charity encompasses more than that.
Or to put it simply, to practice charity is to be compassionate. This is the insight of Marcus Borg who notes, "'To be compassionate' is what is meant elsewhere in the New Testament by the somewhat more abstract command 'to love'" (Meeting Jesus Again for the First Time, 49).