This practice of continuous prayer in the presence of God involves developing the habit of carrying on the mental life at two levels. At one level we are immersed in the world of time, of daily affairs. At the same time, but at a deeper level of our minds, we are in active relation with the Eternal Life. I do not think this is a psychological impossibility, or an abnormal thing. One sees a mild analogy in the very human experience of being in love. The newly accepted lover has an internal life of joy, of bounding heart, of outgoing aspiration toward his beloved. Yet he goes to work, earns his living, eats his meals, pays his bills. But all the time deep within, there is a level of awareness of an object very dear to him. This awareness is private; he shows it to no one; yet it spills across and changes his outer life, colors his behavior, and gives new zest and glory to the daily round. Oh yes, we know what a mooning calf he may be at first, what a lovable fool about outward affairs. But when the lover get things in focus again, and husband and wife settle down to the long pull of the years, the deep love-relation underlies all the raveling frictions of home life, and recreates them in the light of the deeper currents of love. The two levels are there, the surface and the deeper, in fruitful interplay with the creative values coming from the deeper into the daily affairs of life.
So it is sometimes when one becomes a lover of God.Thomas Kelly, The Sanctuary of the Soul
Kelly adds, “How do you begin this double mental life, this life at two levels? You begin now, wherever you are. Listen to these words outwardly. But, within, deep within you, continue in steady prayer, offering yourself and all that you are to Him in simple, joyful, serene, unstrained dedication.”