Our hearts pump at a rate of 70-75 beats per minute. Though weighing only 11 ounces on average, a healthy heart pumps 2,000 gallons of blood through 60,000 miles of blood vessels each day. Every day, the heart creates enough energy to drive a truck 20 miles. In a lifetime, that is equivalent to driving to the moon and back. A healthy heart can do amazing things. Conversely, if our heart malfunctions, our whole body shuts down.
The same could be said of our "spiritual heart". In Scripture, the word heart represents the center of our emotions, thinking, and reasoning. It is the "command center" of our life. So when we read, "Keep your heart with all diligence" (Prov. 4:23), it makes a lot of sense. But, it's a difficult advice to keep.
Life will always make demands upon our time and energy that cry out for immediate attention. By comparison, taking time to hear God's Word and to do what it says may not shout quite so loudly. We may not notice the consequences of neglect right away, but over time it may give way to a spiritual heart attack. I'm thankful God has given us His Word. We need His help not to neglect it, but to use it to align our hearts with His every day. To keep spiritually fit, consult the Great Physician.