Can anything oppose light? No. There are no adversaries of enlightenment.
Yet, before we can answer the inquiry in a meaningful way, we must understand what enlightenment is and what it isn’t.
Enlightenment isn’t a “thing” or state of mind. It isn’t achieved in time, nor can any individual assume praise for attaining it. It isn’t an experience or milestone that grants domination over the physical world.
“Enlightenment is but a recognition, not a change at all.” – A Course in Miracles
Enlightenment is not a change, it is a recognition. It a re-cognizing of what’s already known. It is seeing everything as it is in Reality, not perception (dualism). Being at the effect of this recognition, there is no sense of separation as a separate “me” from all that there is and thus no suffering. All is seen as ONE as it is in Truth.
The “recognition,” being true, is whole. There’s nothing beyond it. Because it is all-encompassing, there is nothing outside of it that can oppose it. Everything is part of it and no part of it could work against itself. You couldn’t bite off your nose to spite their face even if you tried.
If we use light as a metaphor (which is the root word in enlightenment), can anything oppose light? No. Not even darkness can oppose light. Darkness has no independent existence or autonomous source.Darkness is the absence of light and although light can APPEAR to be blocked, what obstructs the light isn’t contradicting or having any effect on the light or its source.
“A cloud does not put out the sun.” – A Course in Miracles
With the understanding that enlightenment is a recognition the question “What are the “enemies” of enlightenment?” is better asked “What is the block to the awareness of enlightenment?” The underlining assumption in the 2nd question establishes enlightenment here and NOW. And the answer to that question is simply: you believe yourself to be a separate person, separate from others, the world and Source.