This story is told by President Gordon B. Hinckley in General Conference, April 1998, “Testimony”:
Let me tell you a story that I heard recently in Mexico. In Torreón I was driven about in the fine automobile that belonged to the man of whom I speak. His name is David Castañeda.
Thirty years ago he, his wife, Tomasa, and their children lived on a dry little run-down ranch near Torreón. They owned 30 chickens, 2 pigs, and 1 thin horse. The chickens provided a few eggs to sustain them and the means whereby to earn an occasional peso. They walked in poverty. Then the missionaries called on them. Sister Castañeda said, “The elders took the blinders from our eyes and brought light into our lives. We knew nothing of Jesus Christ. We knew nothing of God until they came.”
She had two years of schooling, her husband none. The elders taught them, and they were eventually baptized. They moved into the little town of Bermejillo. They were fortuitously led into the junk business, buying wrecked automobiles. This led to association with insurance companies and others. They gradually built a prosperous business in which the father and his five sons worked. With simple faith they paid their tithing. They put their trust in the Lord.
They lived the gospel. They served wherever called to do so. Four of their sons and three of their daughters filled missions. The youngest son is presently serving in Oaxaca. They have now built a very substantial business and have been prospered therein. They have been taunted by their critics. Their answer is a testimony of the power of the Lord in their lives.
Some 200 of their family and friends have joined the Church due to their influence. Over 30 sons and daughters of family and friends have served missions. They donated the land on which a chapel now stands.
The children, now grown to maturity, and the parents take turns going to Mexico City each month, there to work in the temple. They stand as a living testimony of the great power of this work of the Lord to lift and change people.
They are typical of thousands upon thousands throughout the world who experience the miracle of Mormonism as a testimony of the divinity of the work comes into their lives. (See: https://www.lds.org/general-conference/1998/04/testimony?lang=eng )