I believe in electricity, especially when it bites me...
Though not exactly correct with respect to physics, I've found the water analogy the best in terms of understanding concepts and terms.
Imagine a water tower. The water in a high tower will have more force when it hits the ground than a low tower. This is akin to voltage, a potential of energy
Amperage is analogous to the diameter of pipe from reservoir to ground, a larger pipe allowing more water to flow through a point at a time, in effect.
Power is essentially the energy that can be converted or spent doing something useful over time and is directly related to volts and amps. The same power could be had from a trickle from a very high tower (high V, low A) as from a low tower opened up wide (low V, high A). Applications may vary.
And I've seen water towers, so electricity must exist...