We think that delusion is anything that riddles the mind, until the day we realize that the mind itself is a delusion.
Imagine that there is a major power cut and in that complete darkness you enter your apartment. You are not able to tell what is where, why something is where it is, why you are getting hurt by things again and again, where you are headed or what anything means. You are not able to understand anything. You are not even able to find the emergency light sometimes.
But when the lights are on, you know what everything is — you put it there! You know what purpose every item is serving, what is the plan, how to move things, how to move about in the house, how to manage everything. You own everything and run everything yourself. Even if you accidentally get hurt, you know why that was, and what to do about it.
It is the same apartment, with the same things and people. But when it is dark, it doesn't make sense and can even be scary at times. But when the lights are on, you can easily figure everything out.
Now imagine that instead of that apartment, this is true for the whole world, the entire Cosmos.
Everything other than enlightenment is maya, delusion. — Paramahamsa Nithyananda
The complete darkness is delusion. The lights being on is enlightenment.
When the inner light is turned on, it throws its rays on everything around you, and you see everything as it is. As you keep walking ahead using that light, its radius goes on expanding, and more and more becomes visible and clear. That is the only freedom from delusion, the darkness of the mind.