John Ames has a lot on his mind and little time to put it to paper. He's written thousands of pages of sermons, and he's not about to rehash those here. He's on a mission to speak to his son from beyond the grave.
He writes of his regrets and what brings him sadness: "I don't want to be the tremulous coot you barely remember" (1.14.4). He speaks of his impressions—"I don't enjoy [the television] myself. It's not the last impression I want to have of this world" (1.14.14). And he confesses his failures—"I was downright ashamed to remember how impatient I was for him to leave, thinking only of my own life, I admit" (1.14.30).
Ames's style has a purpose: he wants to present to his son not only his words, but also himself. He wants to come through the text—to be incarnated in it, if you will. For that reason, the writing is very intimate, but it's also not particularly difficult. It's meant to be understood.