It is hard to find something more fundamentally important in golf than the grip. Our hands are the only point of contact with the club—they’d better be on there correctly!
The grip can promote or set the tone for so many things in the golf swing both good and bad. For women, children and beginners it is important to begin with a strong enough grip so that they can create the leverage required to cock the club vertically enough in the backswing. A ten-finger grip is also advisable for this type of player to help them control the unfamiliar weight of the club. A weak grip and a forward ball position are recipes for rolling wrist action instead of proper wrist cock. This rolling of the hands forces the student to use their body aggressively on the way through or roll the hands even more on the way through to square the blade up at impact.
Think of hitting a nail with a hammer. You don't see anyone take a full wind up with their body then try to deliver the hammer with speed. They grip the hammer aggressively and use their wrist to cock the hammer back and tap down with efficient power and contact--sounds like qualities we'd like in the golf swing! However, the only thing that can allow you to begin that process is a correct grip. Try putting your hands on the club and pointing both lines that your index finger and thumb create at your right shoulder.