".... whenever someone turns to the Lord, the veil is taken away. For the Lord is the Spirit, and wherever the Spirit of the Lord is, there is freedom. So all of us who have had that veil removed can see and reflect the glory of the Lord. ...And the Lord—who is the Spirit—makes us more and more like him as we are changed into his glorious image....."
An amazing transformation from darkness (ignorance) to light (knowledge) happens when we accept Jesus as who He claims to be. Until one makes the choice to trust God and accept the Bible as truth it is foolishness and just empty words in an old book, but the moment we believe everything changes. We are able to see everything from a new perspective.
I had cataracts a couple years ago and though I thought I could see pretty good I knew I needed some new glasses so I went to an eye doctor for a prescription because I wanted to see even better than I 'thought' I did. After He examined my eyes he told me I was "legally" blind and needed surgery immediately. I trusted my doctors advice and allowed him to destroy the lens in my eyes and literally suck them out and replace them with a lens that was clear and untarnished.
When I got over the initial stages of surgery and was able to take the dark glasses off for the first time I could not believe what I had not been seeing. Everything had a different perspective and was crystal clear with colors so bright it hurt my eyes to look at them until I adjusted to the new perspective.
It is very similar for those who have not yet accepted Jesus, they are not able to see truth. Here is a classic example of what faith in Jesus does to/for human understanding; "By faith we understand that the entire universe was formed at God’s command, that what we now see did not come from anything that can be seen." No one can believe the Biblical account of creation unless they have the faith that comes from knowing God. To an unbeliever creation is foolishness but to those of us who believe, there can be no other explanation than that God created all and holds all together.
Once the "veil" of darkness is removed from our eyes and we can, by faith see and understand, we have an obligation to boldly reflect that light. As we grow and reflect the "Light" more and more people will begin to become curious about our ability to see and understand things they cannot and will go seeking a "Doctor" to get a new pair of glasses so they can see "more clearly".
Jesus said we are the Light of the world, we have the knowledge that will overtake the darkness and destroy its ignorance and set people free. If we have the Spirit of the Lord within us the we carry with us the freedom and liberty that will set the nations free. Like it or not there is no other answer to the worlds problems.