"Memories" joke

A Minister decided to do something a little different one Sunday morning.
He said, "Today, church, I am going to say a single word and you are
going to help me preach. Whatever single word I say, I want you to sing whatever hymn comes to your mind."
The pastor shouted out, "Cross."
Immediately the congregation started singing in unison, "The Old Rugged Cross."
The Pastor hollered out, "Grace."
The congregation began to sing, "Amazing Grace, how sweet the sound."
The Pastor said, "Power."
The congregation sang, "There is Power in the Blood."
The Pastor said, "Sex."
The congregation fell into total silence. Everyone was in shock. They all nervously began to look around at each other, afraid to say anything.
Suddenly, from the back of the church, a frail little 87 year-old grandmother stood up and, in a tiny quavering voice, began to
sing, "Precious Memories."