Apparently the word agape is a Christian invention.
“… God is love.” ~ 1 John 4:8
In Koine Greek it is: “… ὁ θεὸς ἀγάπη ἐστίν.” <=> “… the Theos agape is.”
(In Latin: Deus Caritas Est, btw)
Dr. Art Lindsley notes something very interesting about this. He says
“The word agape is only once used as a noun in ALL of Greek Literature in Jesus’ time. We have no parallel of it. Only one case where agape is used as a noun. Now the verbal form of agape is sometimes used in Greek literature, but basically Christians took this idea of agape and made it a central plank – put it right at the very core of the New Testament. Essentially agape is a Christian invention.”
Dr. Lindsley also goes on to point out that you wont find such a strong expression of God being equated with love in other religions. For example, you wont find in the Koran a statement, to wit, “Allah is love.”
My notes are taken from a lecture titled, Argument From Agape: Can Love Lead You to Knowing Christ? by Dr. Art Lindsley at the C.S. Lewis Institute.