Keep thy heart with all diligence; for out of it are the issues of life. Proverbs 4:23
“Keep thy heart with all diligence,” is the counsel of the wise man; “for out of it are the issues of life.” As a man “thinketh in his heart, so is he.” The heart must be renewed by divine grace, or it will be in vain to seek for purity of life. He who attempts to build up a noble, virtuous character independent of the grace of Christ is building his house upon the shifting sand. In the fierce storms of temptation it will surely be overthrown. David’s prayer should be the petition of every soul: “Create in me a clean heart, O God; and renew a right spirit within me.” And having become partakers of the heavenly gift, we are to go on unto perfection, being “kept by the power of God, through faith.”
Yet we have a work to do to resist temptation. Those who would not fall a prey to Satan’s devices must guard well the avenues of the soul; they must avoid reading, seeing, or hearing that which will suggest impure thoughts. The mind should not be left to wander at random upon every subject that the adversary of souls may suggest…. This will require earnest prayer and unceasing watchfulness. We must be aided by the abiding influence of the Holy Spirit, which will attract the mind upward and habituate it to dwell on pure and holy things. And we must give diligent study to the Word of God. “Wherewithal shall a young man cleanse his way? By taking heed thereto according to Thy word.” “Thy word,” says the psalmist, “have I hid in mine heart, that I might not sin against Thee.”
You will have to become a faithful sentinel over your eyes, ears, and all your senses, if you would control your mind and prevent vain and corrupt thoughts from staining your soul. The power of grace alone can accomplish this most desirable work.