I don't know who that guy on the train is, perhaps he just wants to spread his religion. So what, many people do be they Jewish or Christian or Atheist. Big deal.
As for the Africans. Of course when the Europeans turned up they were too lazy to catch people themseelves, they just paid a small group of them to catch their own countrymen. Divide and conquer.
Same everywhere. When the Europeans went to India or North America they also paid a small group to betray their fellow men. Exactly the same in the ME, just look at Saudi Arabia.