The effect of our prayers on souls in the next life

Question: Are we not able, through love and faith, to make those on the other side hear of the Cause who had not heard of it while on earth?

 Answer: Yes, surely, sincere prayer always has its effect, and it has a great influence in the other world. We are never cut off from those there. The real and genuine influence is not in this world but in that other. 

- 'Abdu'l-Baha  (From a talk given by ‘Abdu’l-Baha in Paris, France, October 18, 1911; Star of the West, vol. II, no. 6)