How does Marilynne Robinson use imagery in Gilead?

Imagery:

"[My grandfather's] eccentricities were thwarted passion, that he was full of anger, at us not least, and that the tremors of his old age were in some part the tremors of pent grief."

"This morning the world by moonlight seemed to be an immemorial acquaintance I had always meant to befriend."

"He would say peace will come only when that war ends, so the God of peace calls upon us to end it. He said all this with that gun in his belt. And everyone there always shouted amen, even the littlest children."