Of course, geothermal energy will never fun out. It can be considered a renewable resource. It is fundamentally different from non-renewable energy sources like oil. It is a clean source of energy that can replace dangerous methods like nuclear or dirty ones like fossil fuels. Geothermal is a good option for the future.
According to the first law of thermodynamics, energy cannot be created nor destroyed, only altered in form. Following this logic, even geothermal energy is not renewable based on the fact that the energy will be removed from the system with no energy input back into the system. Truly renewable energy sources would be something plant based as more plants can be grown after the energy from previous generations is expended.