When you push on a wall, the wall pushes back on you just as hard as you pushed it. If the wall did not push back, then you would push it over.
Newton's Third Law states:
Whenever one object exerts a force on a second object, the second object exerts and equal and opposite force on the first object.
For every action force, there is an equal and opposite reaction force.These forces are called the action and reaction forces. They are equal in strength and opposite in direction.