March 31

It is a lovely day, the sun shines brightly upon the earth, giving light and warmth to all creatures. The Sun of Truth is also shining, giving light and warmth to the souls of men. The sun is the life-giver to the physical bodies of all creatures upon earth; without its warmth their growth would be stunted, their development would be arrested, they would decay and die. Even so do the souls of men need the Sun of Truth to shed its rays upon their souls, to develop them, to educate and encourage them. As the sun is to the body of a man so is the Sun of Truth to his soul.

A man may have attained to a high degree of material progress, but without the light of truth his soul is stunted and starved. Another man may have no material gifts, may be at the bottom of the social ladder, but, having received the warmth of the Sun of Truth his soul is great and his spiritual understanding is enlightened. 
(‘Abdu’l-Baha, from a talk, Paris, October 22, 1911, ‘Paris Talks’)