Explanation:
It means to acknowledge what others believe, yet still believing in what you wish to believe in. Not bothering other people for what they believe in.
Whittier had used symbolism and imagery of war in his poem "To William Lloyd Garrison" when he described the rural nature of the New England including its cultural atmosphere, as well as its religion. In addition, Whittier was among the most prominent poets wherein among his main subject was the American Civil War.