life force 
noun [mass noun]
1The force that gives something its vitality or strength: the passionate life force of the symphony...
- The term we will give to this life force within us is Vitality.
- You might not like the final product - you might even hate its obsessive and arch re-use of movie and TV history - but you can't argue with its life force.
- To play disc one is to rediscover the swift 4/4 punk stomp as the elementary rhythmic life force it should be.
1.1The spirit which animates living creatures; the soul.As one of her teachers put it, Vicky had such a strong life force, and it is this strength we miss the most about her....
- Until now, the life force that grew with the strength of the sun has been retreating into the fruit and the grain.
- Does being with this person add to my life force or do they rob me of my energy?