And the thing about their flaw, is God has proven himself, many many times. The miracles are still manifesting till this day. It's written, '...and these signs shall follow those who believe...' They shall cast out demons, heal the sick, raise the dead. God does not what us witnessing without proving it. This is how the 12 apostles did it, during Jesus and after Jesus. In the book of Matthew and Acts. You have to prove it, by using the authority God gives you to show it.
These people see the miracle happen, but deny it real. It's written also in the bible, That they will not turn to God, because stepping into the light reproves them of their sin.
And one more thing, It's going to be better for people like Sodom and Gomorrah, then those people, because Sodom and Gomorrah would have gotten saved if they seen it. These people refused to repent from doing evil, even after having seen the proof.