THE heart is a finely tuned instrument. It is also delicate. The "narrow and rough" road of the Gospel, and all the bumps we encounter along the way, can throw the heart out of calibration. Temptations, trials, suffering… they can shake the heart such that we lose focus and direction. Understanding and recognizing this innate weakenss of the soul is half the battle: if you know your heart needs to be recalibrated, then you’re halfway there. But many, if not most professing Christians, don’t even realize their hearts are out of sync. Just as a pacemaker can recalibrate the physical heart, so too we need to apply a spiritual pacemaker to our own hearts, for every human being has "heart trouble" to one degree or another while walking in this world.