Some religions believe the way to eternal life is through moral enlightenment. They believe man passes through stages of growth such as reincarnation where souls experience different stages of enlightenment.
This is similar to what Satan said in the garden of Eden, he told the woman that with sin would come enlightenment. Satan said they wouldn't die, but would be like the god's knowing Good and evil.
Satan's formula was sin led to moral enlightenment; enlightenment led to eternal life. The very opposite of God's teaching. God taught that confession of our sins was more practical than growing to moral enlightenment and perfection. We can grow without achieving perfection. We can be enlightened to know of our sinfulness. Moral knowledge by itself can't save us. It even puffs us up in pride.
The true light is that we will never reach complete sinless enlightenment on earth, but we can know Jesus and the Father. Enlightenment is knowing God and his way of life. Knowing good and evil isn't the same as knowing God. God is eternal, God is love, God is light and in him is no darkness.
1 John 2:4
He that saith, I know him, and keepeth not his commandments, is a liar, and the truth is not in him
Disobedience shows we don't really know God the way we could. Disobedience proved Satan doesn't really know God. Sin doesn't make us know God better. Sin caused separation vs union.
Whether Satan really believed moral enlightenment brought life I don't know, but it is possible he really believes it. Many human religions do seem to come from this way of thinking.