This illusory world is one of perception, because it is created on a belief in separation. When you believe something, anything, is separate, you "perceive" what it is as outside or separate from you. In Oneness, there is only knowledge, which reflects no separation. When you are the Oneness, there is nothing separate from you to perceive. This is why your perceptions/beliefs/opinions have no meaning, because they are based from a view of separation. Knowledge or Truth is what you already have and what you already are. When you release your false beliefs/perceptions, Truth is revealed as always having been there.