answering a higher calling

To act in service to a higher i.e. more noble cause, a greater good. Often indicating an action undertaken at the behest of a Higher Power, such as a supreme being or deity, or some conception of justice and the morally right; motivation for personal growth and/or individual sacrifice for the greater good.

The lawyer quit her lucrative position as a private defense attorney and instead became a low paid public defender because she was answering a higher calling.