Now I've had some time to watch the video.
It says why does God rely on humans to spread the Gospel?
God simply wants to do it that way. Man messes up, it seems, and we have 3000 different churches everywhere. But still, the message is getting preached.
Although God uses preachers... Romans 1:19 says God can be seen in nature already, as the video points out.
However, Romans 10:14 says if there's noone to teach the word... there can't be faith. This is my understanding of that verse, in lights of Acts 8:31.
At this point, the four gentlemen in the video start laughing implying there might be a contradiction.
Since this is one of your first doubts, let me answer to this from my perspective.
Romans 10:14 doesn't present a contradiction to Romans 1:19. The latter verse merely says God can be seen in nature.
I would conclude, you can somehow "catch" God in nature even while you don't have faith.
In my opinion, you can somehow feel God and still be 100% caught in doubts.
This is how I would reconcile this.
Thomas