Ego

An ego casts a shadow and hides the light of truth.

A small ego thinks, a big ego knows.

An ego is what we think. Thinking is the ego. As soon as we start to think from when we are born we start to think and form ideas and opinions. Ideas and opinions are not in themselves bad. What makes them bad is our attachment to our idea or opinion to the extent that we believe them to be the ultimate truth.
The amount of the attachment that we have to our ideas and opinions is the amount or size of the ego that we have.

The more attached we are to our ideas and opinions, the larger our ego becomes. The shadow that is cast from such a large ego does not allow the light of truth to be seen by others. It may appear as truth, but truth cloaked in the shadow of ego is deflected by the egos selfish motives.

By true honesty and letting go of any idea of self, is the only way that our inner light of truth can shine through to others.