A teenage boy had just passed his driving test and inquired of his 
father as to when they could discuss his use of the car. 
His father said he'd make a deal with his son: 
"You bring your grades up from a C  to a B average, study your Bible a little, 
and get your hair cut. Then we'll talk about the car."
 
The boy thought about that for a moment, decided he'd settle for the 
offer, and they agreed on it.
 
After about six weeks his father said, "Son, you've brought your grades 
up and I've observed that you have been studying your Bible, but I'm 
disappointed you haven't had your hair cut."

The boy said, "You know, Dad, I've been thinking about that, and I've noticed in my studies of the Bible that Samson had long hair, John the Baptist had long hair, Moses had long hair, and there's even strong evidence that Jesus had long hair."

The father responded: "Did you also notice they all walked everywhere they went?"