To believe an illusion is to fail to RECOGNIZE that it is an illusion, but instead we are recognizing it as a reality or truth which it is not. We're not seeing correctly, so have blocks in our perception.
When you can RECOGNIZE that an illusion is just an illusion, that means that you realize what you thought it was wasn't true, it is completely false, AND it is not REAL.
There is a significant power in discerning the difference between an illusion and reality. Only when you can see and acknowledge that something is a completely false illusion which really is not there and has no reality to it at all - that in truth it does not exist whatsoever, then you are recognizing that it HAS disappeared because it was never really happening to begin with.
Once recognized, ie seen clearly and correctly, the illusion is no longer believed in, it is accepted as being not there, is gone already, never happened and never really existed. This is UNDOING. Whatever that illusion was it must then disappear because you recognize and believe it no longer is true and so are no longer willing to MAKE it or sustain it. This translates even to the extent of physical healing if the physical "issue" is fully recognized as completely illusory and not a real sickness.
I saw this because yesterday I got a surprise sunburn and decided to use it with Holy Spirit to learn more about healing and forgiveness. As I worked with it, I eventually came to see that I didn't even have a "real" sunburn, I had an ILLUSION of a sunburn, and was then able to withdraw my belief in it.
I eventually was prompted by Holy Spirit to realize it is "already gone", which reminds me of a Greg Braden video where he's in a hospital in China where they affirm "already gone" as a way to undo sickness in a short space of time.
When we are sick in some way, we are tempted to believe it is REAL, to believe it's happening and exists and having an effect on us. That we're being caused by it, it has power, it's got truth in it. We're tempted to then fight with "it" but really we're fighting with the illusion of a FAKE sickness that we believe is a real one. ALL sickness is fake. There is no truth in suffering. Recognizing the ILLUSION of sickness as an illusion deflates and disempowers it.
Today my sunburn is a lot better already. I can't scientifically say, hey presto, this change in attitude produced X amount of healing, but I did learn more about the undoing of sickness and how to better recognize an illusion when it is one.
There is no such thing as real sickness, all sickness is an illusion of separation seeming to be real.
If you have cancer, you don't have "real cancer". There is no such thing as real cancer. There is only an ILLUSION of cancer. If you have a broken leg, you don't really have a broken leg, you have an ILLUSION of a broken leg. If you have brain damage, you don't have real brain damage, you have an ILLUSION of brain damage. It's a fiction. Like a pretend image which you're holding in place. Something you made up, literally.
This is why dead and sickness can be abolished because you MADE THEM. They are not true or real at all.