You write, “To say that the world is an illusion seems to me to be a theory. Many people in the world are suffering. Do you think that you could convince such a person that his or her suffering is an illusion?”
When you close your eyes for the last time, what do you consider will be your conception of the “reality” of this world? Is it possible that, in the process of death, all forms will fall away from consciousness? What is the reality of the “world” in your deepest sleep? This, I submit, is the meaning of “the world is an illusion.” And, in that same sense, there being no world, what then of the “reality” of suffering?
You say, “I want to perceive reality as reality, and illusion as illusion.” Both will disappear as distinctions, it would appear, at death—as they do in deep sleep.
What would your awareness consist of if you were to dismantle your tendency to consider matters in terms of “should” and “should not”? In your deepest sleep, is there anything which you conclude “must be” or “must not be”? When you draw your last breath, what will become of these ideals you have, concerning some preferable state of awareness?
Whatever state of awareness is present is “reality.” Any desired state of awareness which is not present (but “should be”) is nothing more than an idea about awareness, an “illusion” in the definitional sense—“not in accord with the facts.”