"God Only Knows" was a regional hit for Philadelphia Doo wop group The Capris.
[1] It was hastily written and together with five other songs it was recorded by The Capris with their very recently acquired female singer Renee Hinton on lead vocal.
[2][3] According to Charlie Stroud (who was to leave the group before Renee Hinton joined[4]), he sang the song first and didn't like it.
[5] The singer is singing about how only God can know how deep her feelings are and how she is worried that their relationship is breaking up.
[6] On hearing the song, Marvin Gaye said that it fell from the heavens and hit him between the eyes.