That's because the island was invaded by pretty much everyone even though it was originally a French colony. British and Spanish armies also intervened and every time that the people would win and take control of the island, the French would just send numerous new soldiers to retake it. Just during Napoleon's era, 50 000+ soldiers died from yellow fever only.
Most slaves worked on Plantations
They adopted Christianity because it was the same religion as they're European masters at the time.
