The Practice of the Presence of God is short, simple, and effective.
On its length, I could have read the entire book in an hour and half or less. It is a collection of letters written by Brother Lawrence, recounted conversations with him, and it ends with a brief story of his life.
It is so short because it is so simple. There is no need to delve into many different aspects of the topic. The message is this: Practice the Presence of God. No matter what you are doing or where you are, God is there with you. Never forget that. Constantly practice the recognition that He is near and be in constant communication with Him. Simply open yourself up to His presence and feel His love for you and pour out your love and thanksgiving to Him. Each task should be done out of love for Him.
Finally, the simplicity of the topic also makes it greatly effective. Despite the book being so short, I took two weeks to read it, and I'm glad I did. I need that simple reminder said to me over and over in different ways. It is so easy to forget the presence of God. We may study Him, think about Him, talk about Him, but never remember simply that He is with us at every moment. It is so easy to get caught up in our daily tasks and forget His presence in our life throughout the entire day.
Thank you Jesus for giving us Your righteousness, allowing us to know and be known by God!