If a person was standing before you and you asked them if they were conscious, what is their answer?
Do you believe them? Why? You cannot verify the answer as being correct.
Sufficient AI would have you convinced that it is conscious, self-aware.
Would it actually be? if not, why not?
How can you show that your own consciousness is not simply a complex-enough AI system to fool others and even perhaps yourself? Would that mean you are not conscious?
Aside from complexity, what is the difference between you and Mario (from Mario Bros. games)
If consciousness cannot arise from non-conscious matter alone then there would have to be a conscious creator of us. Assuming we are actually conscious.
If it can arise from non-conscious matter alone then we should have seen some evidence of that already and we should perhaps be able to design conscious systems already. That would put us in the role of the conscious creator but then we have to ask ourselves: 1. are we perhaps just carefully adjusted matter arranged just so, on purpose by a higher-level conscious creator? or 2. are we the top-level of consciousness, somehow self-assembling from the soup of matter that is the "universe"? 2nd option there makes some folks more comfortable but it is less reasonable and more illogical than option 1.
How can we know?
Perhaps its turtles all the way down.