Best explaination to why magnets energy is inexhaustible? I have explained the Lorentz Force briefly to a group of kids, they raised some questions, 
why does magnet force is inexhaustible?
We have put a magnet held by a rope, tied to the floor, to levitate, sustained by the energy of another magnet above (of course it could stay like that forever if no other force is present between the 2 magnets) so, 
First Question where is this "permanent" force comming from?
Second Question what is the reason because it can even defy gravity? in a permanent fashion? 
Third question: If we believe, Newtons third law, that in every interaction, there is a pair of forces acting on the two interacting objects, what is the force interacting on magnets and how are they linked to that force?** 
Thanks.
 A: It seems there's nothing specific to magnets in your question - it could equally well be any other force.

where is this "permanent" force comming from?

This presumably comes from the idea that you need to "do work" (a technical physics concept) to exert a force. That seems to works for humans - if you push against a wall you get tired even if the wall doesn't move - but it's not true in general. You only do work if you exert a force and move in the direction of the force.
There's nothing special in physics about just exerting a force. After all, you feel the Earth's gravity, and that's also a "permanent" force.

what is the reason because it can even defy gravity? in a permanent fashion?

Why can't it? A force that's equal in magnitude and opposite in direction will "defy gravity". In the same way the electric forces between your shoes and the ground stop you from falling into the Earth's center.

If we believe, Newtons third law, that in every interaction, there is a pair of forces acting on the two interacting objects, what is the force interacting on magnets and how are they linked to that force?**

The "other force" is the force exerted by the other magnet on the first one. For example say you have two magnets A and B, and A exerts a force of $10 N$ on B. If you run through the calculations you'll also find that B exerts a force of $10 N$ on A. This is the reaction force alluded to by Newton's third law.
It's really not that special: the Earth exerts a gravitational force on you equal to your weight, and you exert a gravitational force on Earth equal to your weight.
