Ray Of Light Meaning

(idiomatic) an inspiring or enlightening person or thing

Example: 2009, D.M. Armstrong, Quadrant, November 2009, No. 461 (Volume LIII, Number 11), Quadrant Magazine Limited, page 5:
  I think he was somewhat lost for a political position - a simple conservatism did not attract him - and I make the guess that Arnold had been a spar that he got hold of as he struggled to find a political position. I was certainly in that position, having been persuaded by Anderson, especially at the lunch-hour meetings of his Free-thought Society, of the bankruptcy of the Left. Arnold came to me as a most welcome ray of light.