How we cite our quotes: (Letter.Section.Paragraph)
Quote #7
…when I see you, at the end of your good long life, neither of us will be old. We will be like brothers. That is how I imagine it. (1.15.35)
Ames doesn't imagine heaven as a place; he thinks of it a time of resurrection and restoration with those who, like him, have died. He imagines a glorified state of youth, where fathers and sons are more like brothers.
Quote #8
I do hope to die with a quiet heart. I know that may not be realistic. (1.15.120)
Even close to death, Ames worries about what tomorrow will bring. He figures his heart will be restless until it rests in his God.
Quote #9
I'll pray, and then I'll sleep. (2.21.149)
The final words of the letter—and the novel—speak to the old man Ames has become. He's a mortal man who finds usefulness in prayer, and sleep, which he almost certainly does more of these days, is sort of like death. Ames is preparing for his final rest.