Eliot evidently never got the memo re: not talking about religion, because Silas Marner is one God-rumination after another, exploring several different ways of thinking about religion. A little historical background: in the early 19th century, when Silas Marner takes place, the Anglican Church was the official, state-sponsored religion of England. People who didn't belong to the church were called Dissenters, and they went to "chapel." There were many different types of Dissenters, but many of them were Calvinist—they believed that you were either saved or not, and there wasn't anything you could do about it. Conflict between Anglicans and Dissenters is a major issue in a lot of 19th-century novels.
In Silas Marner, there's Silas, who comes from a Dissenting, Calvinist Church; there's the official Anglican religion of Raveloe; and then there's the superstitious, folkloric beliefs that both Silas and the villagers practice, full of household gods and ghosts. What's the purpose of religion, and what kind is best? Eliot doesn't give a straight answer, but you may have an idea by the end of the novel.
Eliot expects her readers to have a more sophisticated understanding of religion than her characters. Their simple religion is appropriate to a rustic village, but not to the readers of the novel.
Silas Marner is critical of Dissenting sects and suggests that Dissenters should re-enter the Anglican church.