Thomas Brooks:
“Guarding the mind and the heart is a sacred duty incumbent upon every believer, for it is from these inner chambers that the issues of life flow forth. The Puritan must be vigilant in the discipline of the mind and the heart, keeping them focused on that which is true, honorable, just, pure, lovely, and commendable. Let us not allow the seeds of falsehood and impurity to take root in our thoughts and affections, but let us cultivate the soil of our inner being with the truths of God’s Word and the graces of His Spirit. In this way, we will be fortified against the assaults of the enemy and equipped to walk in the paths of righteousness all the days of our lives.” (From “Precious Remedies Against Satan’s Devices”)