Just because unregenerate humanity suppresses the truth, that does not mean that they do not know the truth, at least on some level.
Apostle Paul makes reference to pagan Greek poets who make truthful statements in their writings, and their words will forever be found in God’s word. Paul makes it clear that people who do not know God have a basic understanding about Him.
God has placed the longing for eternity in our hearts, and He has revealed Himself to every person in a general way. Everyone sees His majesty in creation, and everyone knows that there is something wrong with humanity and creation in general.
Take for example the following lyrics from the anger-driven rock band Linkin Park (I advise youth to not listen to this genre of music):
“I don’t know what’s worth fighting for
Or why I have to scream.
I don’t know why I instigate
And say what I don’t mean.
I don’t know how I got this way
I know it’s not alright.
I’m breaking the habit tonight”
In medicine we deal with symptoms which lead to a diagnosis and then a solution.
These lyrics provide the symptoms of a serious problem, but they do not provide the diagnosis nor the solution for this problem. These are the symptoms of the corruption sustained by humanity as a result of original sin. Everyone knows that humanity “it’s not alright,” but not everyone is willing to accept the reason why we do evil acts and the reason for the existence of death.
Paul tells us the diagnosis in Romans 5:12
“Therefore, just as sin came into the world through one man, and death through sin, and so death spread to all men because all sinned…”
And he tells us the solution in Romans 5:18-19
“Therefore, as one trespass led to condemnation for all men, so one act of righteousness leads to justification and life for all men. For as by the one man’s disobedience the many were made sinners, so by the one man’s obedience the many will be made righteous.”
Paul is of course talking about the sacrifice of Christ in place of sinners who believe in Him.
It is not enough to know that we are “not alright.” That is the first step in acknowledging a fundamental truth, but it must be followed by two other steps: accepting the diagnosis of sin and embracing the solution.
The solution is none other than Jesus Christ.
In Him we receive righteousness by justification!
Delight in Truth 
Dr. Carl Baugh, whom many think is a quack, has stated the same, Delight.
On his television program, “Creation in the 21st Century,” Dr. Baugh makes four statements about the nature of man. I don’t remember what they are, but they restate what you have noted about man knowing the truth on some level.
I think Dr. Baugh is a brilliant man, in spite of his critics, and have been to his Creation Museum in Texas. Talk about a David and Goliath Story. Just down the road is Dinosaur National Park where I had my picture taken with dinosaur footprints. The Park is a “showpiece” for evolution and I’m glad it’s out in the middle of nowhere (although close enough to Dallas for many school children to be indoctrinated) so that it doesn’t get, hopefully, a lot of traffic.
I like your medical “take” on this issue. The verses you have shared from Romans give us the diagnosis and the solution.
Now if we can get those who suppress the truth to acknowledge their true Creator.
We must ask for the Holy Spirit’s guidance to help others to see the truth.
Thanks for the input regarding creation education, Chris. As a young kid going through high school and bio major in college I too was indoctrinated with humanism and evolution. Too bad I did not study the Bible at that time in my life and I did not learn any apologetic tools regarding creation. I believed creation, but I did not know how to defend it. Times have changed… and God made me realize that I have to dive deeper in His Word and study topics like creation in order to help youth who are in my situation from 15-20 years ago.
But millions prefer to look at the speck in his neighbors eye, rather than the beam in his own.
here’s a painful truth: I would add ‘millions of christians’ prefer to look…