Why did people think Galileo's teachinga are hertical

The church (Christians) believed that the Earth was the center of the universe such as many before them along with most of society because before that Copernicus's idea was little known of. People didn't agree with Galileo because for centuries they had had a different belief even though he could prove it with his new invention, the telescope. The heliocentric theory was not really a widespread belief until centuries later.