Knowing God exists through the work of His hands (creation) is a far cry from understanding the gospel.
The natural man knows God exists through creation, which proclaims His glory.
Still, the natural man cannot comprehend the spiritual things of God.
He can not even receive them.
I wonder what it is about those Biblical truths that get people so riled up.
Things like the natural man being hostile in his mind toward God.
Free willers absolutely hate that Bible truth.
Being taken captive to the will of the devil, being a lover of darkness and a slave of sin, supressing the truth in unrighteousness, unable to obey... yeah, the list goes on and on and can get quite long but free willers contradict all of them.