According to Russell mysticism sees evil as "illusory".  What does he mean by this?  What is his criticism?

Mysticism is an altered state of the human mind,this may be due to religion,spirituality,how one was raised or many other factors that affect how the human mind perceives life. It is life a form of closed mindedness. Mysticism exists because of ignorance,what is oblivious to you is mystic to you. The human mind tends to polarize everything on earth,something will either be good or evil to you,there is no in between.Evil comes in many forms and poses many problems and there is a vast spectrum of evil,from the "greater" evil to the "lesser" evil. Since good and evil is a judgement of the human mind,it leads to the question, are all judgments of good and evil true? or is everything an illusion? Might the aspect of good and bad actually be an illusion? Is evil an illusion?

Step-by-step explanation

Russel is a moral philosopher and a profilic atheist writer.

Mysticism maintains that evil is illusory,and sometimes maintains the same view in regards to good. What Russel meant is most of the reality that we perceive as human beings is actually a subjective illusion, particularly evil. This is because they are based on beliefs revelations and not science. A revelation is a religious source of knowledge against science. It has not been tested and confirmed and there is no correspondance with facts. Science is neutral and credible because evidence is presented,revelation is not. Russel argues that the greatest religions in the world are what is harmful to man as they greatly differ. He argued that religion is mainly based on fear and states that its no wonder cruelty and religion go hand in hand. He argues on why an all knowing and loving God would let such cruelty on earth,create free will of good and evil,rules and those who do not follow his rules are evil. This led to one of his books,"Are the troubles of the world due to decay in faith?" Yet when evil happens ,God is absolved of it. He spent his life thinking about the validity of religion which he found unconvincing and later concluded there is no free will,because if you have free will and still go against the laws of God what you did is evil. He dwelved deeper on the mass murders that go on every day and how states spend revenue just to kill other people and compared it to the killings that happened in the Bible.Are all those atrocities really evidence of an intelligent creator? Him supporting others to kill others and siding with wars? If the creator Himself did this,is there really evil? He is the only perfect spiritual being yet he empowered some of his leaders to kill, washed the whole human race away by floods when they went against his will.The same God led his leaders to raid others and forgave the evil of some of his leaders .So is murder really evil or it is an illusion based on our religious belief when Jesus came and told us not to kill? All this sparks controversy.