Question

Energy can neither be created nor destroyed in the context of this statement explain why do we talk about energy crisis

Answer 1

The conservation of mass states that energy can neither be created nor be destroyed.
Energy can be transformed from one form to another.
For example, if we take some hot water in a beaker and leave it for some time, it's temperature will decrease, it will have the room temperature.
In the above example heat is released and water gets cooled down.
But anyhow can we collect the heat which was released to heat the water back???
No
The energy from the convenient for gets transforms into less convenient.
So we hear energy crisis.

Answer 2

It is true that energy cannot be created or destroyed.

Energy on Earth exists in terms of chemical energy in substances, kinetic energy in water in rivers, heat energy from Sun , wind energy etc.

We are consuming all these and making many products useful for our lives. Due to using the energy in various forms, we are increasing the temperature of Earth's atmosphere.  We are using a lot of burning and heating. So temperatures are going up.

Various fuels with chemical energy in them are being burnt. So they are becoming hot gases in air. They are polluting air.

Thus we are converting energy form a useful state into heat energy of atmosphere and into unusable waste products too.

These processes are not reversible.  To restore energy back to its previous state, it takes much more energy.

So we have energy crisis. That one day all fuels may be used up. Prices will be too high. Pollution will be too much.