David icke isn't the first person who came up with his views/perspectives or ways at looking at things. I am not saying this because I have anything against him. In fact I support his work as one of the few people who are working on waking up the mankind.
I noticed he has misconceptions about religions but if you read religious doctrines deeply you will notice the prospective on the reality is actually the same.
It is all about your perception. Some of the similarities he speaks about are for example our reality is an illusion. Religious texts especially abrahamic religions also believe in the same thing. That this life is a temporary a world of deception. There is an enternal existence; christianity describes it as the kingdom of God. Islam describes it as the hereafter. We are spirit beings in a form of bodies.
In fact, monotheism which is the belief of one God emerged from the concept of oneness.
These religious books also talk about the devil - The Evil spirits who deceive us in order to astray away from our unique consciousness: divide us away from our oneness.
The unique thing about Icke is he relates all these to our modern societies and future predictions. Evil is simply the implementation of what astrays mankind away from our true consciousness such as manipulation for individual gains; lack of empathy; deception..etc
I don't know if you have the bible or the quran. Read the story about moses and pharaoh in the Quran for example. It speaks about this powerful elite pharaoh who uses manipulative power to oppress the people it speaks about magicians he used for his propaganda. What magicians do? They deceive our perceptions.
Surprisingly in our modern days; same thing are happening but with mainstream media; mainstream propaganda all set to achieve an agenda to drive humanity away from their consciousness and to control our perceptions.