You shall love the LORD your God with all your heart, with all your soul, and with all your might. And these words which I command you today shall be upon your heart. You shall teach them thoroughly to your children, and you shall speak of them when you sit in your house and when you walk on the road, when you lie down and when you rise. You shall bind them as a sign upon your hand, and they shall be for a reminder between your eyes. And you shall write them upon the doorposts of your house and upon your gates. --Devarim 6:5-9
The Shema is a most wholesome exhortation of moderation. If we examine what it is saying, at the very beginning and core, it is commanding us to love Hashem in a few different ways. And those ways, if we do them, will help us to love Him in the best and balanced way. Without the complete embodiment of heart, soul, and might, we would fail miserably in our attempt to love Hashem.
heart
To me, when we are commanded to love with our heart, we are using our minds. This part of us takes in knowledge, stores, and uses that knowledge to help others. It is a seat which controls many of our daily actions and helps us to connect with the world. Through the study of Torah and the drinking in of knowledge of the Sages and contemporary writings, we get a sense of what Hashem desires for us and how to be the kind of person He wants us to be. This way of loving our Creator brings understanding and inner growth, and makes us knowlegable in the ways of goodness and holiness.
But what happens when we study too much? We become hardened to prayer and deeds, because we mistakenly think that knowledge becomes complete worship. What about when we study too little? Our ability to comprehend greater knowledge wanes as we start become deficient in connecting with our Creator through prayer, and we start to lose sight of why deeds are important.
soul
Through our prayers and seeking Him, we can love Him and the world by tapping into the Divine and getting guidance. We can grow our souls, cultivate them, and make them sensitive vessels so as to change the souls of others through our inspiration and love. Our avodah molds us, our meditation quiets our souls and informs us, our yearning for the Divine Creator causes us to see deeper than what is around us.
How can too much prayer be a downfall? One might think such a thing can't possibly exist. But truly, if you become so obsessed with prayer, you will lose sight of the need to learn and train your mind, and the need to get on the ground and serve Hashem in a physical way in the world. Too little prayer and soul work? There is no doubt that the answer to that is quite easy: your desire to learn will nearly disappear, as your mind won't be interested in learning the ways of Hashem and your feet won't have the desire to walk in His footsteps.
might
This physical part of our on the ground activity is vital in putting to work what has gone on in the heart and the soul. By taking what we have stored up in the heart/mind through learning and inner growth, and by harnessing our soul power that we have achieved through prayer and daily meditation, we are able to go into the world and serve Hashem with our might. This might could be money, physical work, technical work, etc... In any case, it is outside of the study halls and synagogues: it is our connection to the here and now, the world in our midst.
But what happens if we become obsessed with the physical nature of serving Hashem and lob off the learning and soul work? Quite literally, it is like our souls dry up and the energy to grow our minds is non-existent. The physical takes a toll on the mind and soul. And what if we decide that we are not going to put our feet to the task and get out there and help the world? For one you will not only be a pale human, sequestered from the sun and all daily contact, but your soul will wither from not acting out the beauty it has stored up. This can be compared to a weight-lifter. Does he build muscle up by lifting weights only to go sit in a chair once he has reached his goal? No, he uses that to compete and to grow his title. His muscles are not just for beauty, they are to lift the weights in his competition. Our soul and mind muscles are for us to go into the world and do our job, not merely just to have them as laurels.
Be that moderation that Hashem seeks for us. As we recite the Shema daily, may we truly listen to the moderation it speaks of and learn how to love and serve Hashem our Creator with all of our heart, soul, and might.