The highest spiritual love is the love of man for God, and God for man (agape).
The word can be found in the following quote (John 3:16):
Οὕτως γὰρ ἠγάπησεν ὁ θεὸς τὸν κόσμον, ὥστε τὸν υἱὸν τὸν μονογενῆ ἔδωκεν, ἵνα πᾶς ὁ πιστεύων εἰς αὐτὸν μὴ ἀπόληται ἀλλ᾽ ἔχῃ ζωὴν αἰώνιον.
“For God so loved the world, that he gave his only Son, that whoever believes in him should not perish but have eternal life.”
This same love can also be experienced between two people, in the love between soul mates.
The term is also found in early Christian customs surrounding a shared communal spiritual feast, called the agape feast. This meal was often associated with the Eucharist, and was an early Christian custom.
As two people consume one another in spiritual love – agape forms the center of married life and God is found in the middle, and soul mates search for eternal life in each other’s shared embrace, within which God forms the cornerstone of the loving relationship.