Prayer obtains what it is due to obtain — not what I personally want to obtain, which is different. It is useful that islands of prayer exist in the world, even if they are composed of only one person, or two, or three, or four.
Each person, no matter how old, has an important work to do. This good work not only accomplishes something needed in the world, but completes something in us. The work we do in the world, when it is true vocation, always corresponds in some mysterious way to the work that goes on within us.