Answer:
The Catholic Church strongly opposed the spreading of the heliocentric theory because it meant that the holy book of Christianity, the Bible, was wrong, and that what they were propagating for centuries that the Earth was the center of the universe and that everything circles around our planet was a lie. This was going to make a big damage on the credibility of the church and the skepticism towards it would have grown more and more. The church, considering it had the power, was using all measures possible to stop this, so lots of scientists found themselves imprisoned, hanged, burned alive, killed brutally.