Quotes from Rosemary Dew

I believe in God and feel his presence, but I am intrigued by John 10: 16: "Other sheep I have, which are not of this fold: them also I must bring, and they shall hear my voice; and there shall be one fold, and one shepherd." Since He sought the rest of the world, how do I know he didn't reach them? He appeared to us in a form we could understand—why not to others within the context of their cultures?