Comparing Norse or Greek or other mythological gods with The God of the Bible is like comparing Tom from Tom and Jerry with a prowling lion in the Serengeti. (It should be noted that an overly-sheltered person who has been duped in to believing that all cats are like Tom will have quite the awakening on his first safari.)
One of the most obvious differences between Thor and Jesus is that no one ever claimed to have walked with Thor as he traveled from Oslo to Stockholm. There are no eyewitness accounts of Thor walking on the water in a particular Norwegian fjord. No one can name the mayor of Helsinki when Thor was arrested for smashing part of the city with his hammer.
But perhaps the most consequential difference which those like Mr. Barker make great efforts to miss is that Thor had no power to change the hearts of people, and thus no power to shape what matters in human culture. No one ever sold all their possessions to start an orphanage after being enamored with the love of Thor. No one has risked their lives in places where Thor is hated to tell others of his life-giving power. Thor has not inspired anyone to give of themselves in sacrifice for the least of these. There have been no universities established for the development of the mind and the glory of Thor.
It would be good for Mr. Barker to pause and imagine a world void of every orphanage, hospital, charity, and university established by people with specifically Christian convictions. We can be confident it would be a world neither he nor any of his atheist friends would want to live in.
With piercing irony, the last point in his speech is that the greatest evidence that God doesn’t exist is the suffering and unanswered prayers that take place in a children’s hospital. Of all the hospitals across the western world where sick and suffering children and their families are cared for (and often healed), how many have names like “Saint Jude” or “Baptist” or “Good Samaritan” or “Mercy”? There are no Saint Thor’s Hospitals.