Emotion.

That raw, organic passion, captured in a moment of worship. Singing at her sister's wedding makes the moment bittersweet, but full of beauty. 

Emotion: Passion. 

pas·sion  (pshn)
n.

1. A powerful emotion, such as love, joy, hatred, or anger.

2. Boundless enthusiasm

{To Lucia: Please choose your favorite of the two: I loved the cross-processing on the first, but the second is straight from the camera, and I like it as well. If you meant only one per person as in I myself have to choose, then please let me know(; Thanks for hosting!}