God is good. He creates only Good. Autonomy is good. Autonomy is good because we can choose to do good. Without consciousness, awareness of what one is doing and choosing to do, personal autonomy is meaningless. Therefore consciousness must be good.
Sin is evil, because it perverts the autonomy gave us to do evil. God did not create sin, he created beings capable of sin. A conscious, autonomous being corrupts himself by choosing to sin. The mere capacity to sin, however, does not itself negate the innate goodness of the autonomy to choose to do good. Indeed, it is a necessary evil, for with no choice, the autonomy to choose to do good is meaningless.
Consciousness is good, firstly because God created it, and because of it allows an autonomous person to know when he can and does choose do good.