The book is not a treatise but a record. It gathers four conversations a visitor held with a Carmelite lay brother in Paris in the 1660s, together with fifteen of his letters of spiritual counsel. Brother Lawrence, born Nicholas Herman in Lorraine, had been a footman and a soldier before entering the monastery as an unlearned lay brother, where he worked many years in the kitchen.
His central practice has a plain name: keeping himself in the presence of God. He resolved to recognize God as intimately present at every moment, to speak to Him frankly through the day, and to refer all his work to Him. Over time this attention became habitual, until, he says, it was as hard for him to forget God as it had once been to remember Him.
What makes the account distinctive is its setting. Lawrence locates this communion in labor he disliked, buying wine for the house or working amid the noise and clatter of the kitchen. He insists the time of business does not differ from the time of prayer, and that he could possess God in the bustle of cooking as fully as while kneeling at the sacrament.
His counsel is gentle about failure. He fell often, confessed the fault simply, and resumed his practice as if he had never strayed, refusing to dwell on his lapses. He distrusted elaborate methods and penances pursued as ends in themselves, holding that they are worth nothing apart from the love of God, which is the real aim.
The letters press the same point on others: love God in pains and pleasures alike, seek Him often by faith, and remember He is already within rather than far off. A brief lifting of the heart, even on the march with a sword in hand, is genuine prayer. The book closes with Lawrence near death, still counseling that all God sends is for our good.