"I love thee to the level of every day's / Most quiet need, by sun and candle-light."
The speaker emphasizes that, while her love for her husband may be passionate, it is also mundane and down to earth. She needs this love to sustain her on a daily basis. As the days pass—marked by the passage of time, symbolized by sunlight and candlelight—her love fills her time and fulfills her quiet but important need to survive from one day to the next. Her love for her husband is a life force, just as the sun symbolizes life.
"I love thee with a love I seemed to lose/With my lost saints."
The speaker makes an ambiguous reference to a love she once felt in the past. It is insinuated that she once looked up to figures that were on the same level as saints. They may be actual religious figures, or perhaps they are people in her life whom she revered. In any case, something caused her to lose her admiration for them, and she feared the love she was once capable of feeling was completely lost. In fact, she did not lose her capacity to love, as she now loves her husband on the same intense level.
"If God choose,/I shall but love thee better after death."
At the poem's conclusion, the speaker states that only God can choose whether she will be able to continue loving her husband after death. Up until this point, the speaker seems to be in control of her will and chooses to love her husband passionately. However, the mention of God at the sonnet's end indicates that the speaker believes in a higher power who can dictate whether or not her love will indeed be immortal. She wishes to convey the idea that she loves her husband tremendously, to the point that she believes she could still love him even more when she is gone if given the chance.
