When we do not observe any effects of a force,does it mean that there is no force acting on an object.pushwall

I learnt that when there are effects, a force is acting on a particular object. But when one pushes against a pillar, one is acting a push force on the pillar. But yet I can't see any effect. So, is my question true?

You can easily have a force producing NO effect.

For example a book resting on a table still has gravity trying to pull it down, but it doesn't move. This is because the pull of gravity is balanced by another force - the upwards supporting force of the table on the book (this force is sometimes called the 'reaction').

If you suddenly pull the table away, then you will see the pull of gravity making the book fall down, because there is no other force to balance it.

Whenever you have an unbalanced force on an object (a force that isn't cancelled-out by another force) then the force makes the objet accelerate.

When you push on a wall, you aren't just pushing on the wall.
The wall is attached to the ground or building, which is attached to the Earth.
If you give a force of 100N to the wall, 100N acting on the entire plant will not have a noticable effect.
The effect you do notice if you push hard enough, is that you move backwards.
Newton stated that for every force, there is an equal an opposite reaction: ie. if you give a force to the wall, it gives a force to you in the opposite direction. THIS is the effect YOU notice, not the wall moving around!

no, it simply means that the forces have cancelled each other out, making the net force zero. When you push up against the wall, the wall pushes back against you in an equal yet opposite direction.