(This is a story that comes from Gary Zukav's book "Soul to Soul". I include it here because it is very touching and it can reach us on a level where the soul speaks directly.)
At one of the retreats that Gary and his wife holds and attends, he recounts the experience about a woman in the group who was having a very hard time. The woman shared her frustration with her group concerning the difficulty she was experiencing in caring for her mother who was in the advanced stages of Alzheimer's disease.
Some days the mother would think her daughter to be her mother or her sister, no longer correctly recognizing her as the daughter. And the woman mostly went along with this until one day, she reached a point where she could not take it anymore. She told her mother that, no, she was not her mother. The old woman then stated "You are my sister". And again the suffering, frustrated woman told her mother that no, she was not her sister.
Her mother, who had never been a religious nor metaphysical person all her life, looked directly into the eyes of her daughter and said, "I don't know if you are my mother. I don't know if you're my sister. I only know that my soul needs to be with you."