How Paul Applied Hebrews 11:1 at Romans 1:20
"The evident demonstration of realities though not beheld" - (NWT) "The evidence of things not seen" - (KJV)
Here is how Paul reasoned in his letter to the Christians living in Rome:
"For God's invisible qualities areclearly seenfrom the world's creation onward, because they are perceived by the things made, even his internal power and Godship."
Paul seems be reasoning from the basic principle that when we see things that is made (i.e. the evidence) we can have the assured expectation (i.e. faith) that someone made them.
But how much evidence it takes for people to put faith in God varies. Some may only require the slightest, unscientific amount of evidence. But others may require a lot of highly technical evidence in order to have faith ("the assured expectation") that God exists.
One final thought: I realize that there is more to it than just the evidence no matter how unequivocal and undeniable it may be. There must be a willingness to believe. If someone does not want to believe then no amount of evidence will cause them to believe.
But Paul felt that there is so much reliable evidence that proves that God exists that if someone is aware of it and concludes that God does not exist then "they are inexcusable." In other words, as far as he was concerned there is no excuse for someone to see the things that are made and conclude that nobody made them.
Don Cameron