The Cross of Christ is the only shield against evil, and the mind fixed there is kept in perfect peace. You plead for protection and a right mind, then see that you stand nowhere else. Evil cannot touch the soul hidden in the wounds of Jesus, for the blood speaks better things than the blood of Abel. But a right mind is not a mere calmness of reason; it is the mind submitted to God, the mind that says, "Lord, what will You have me to do?" and then does it without question. The carnal mind is enmity against God, and its imagined peace is a falsehood, a sleep of death. True safety is found when you yield all, your thoughts, your affections, your memory, fallen as they are, to the cleansing flood.
Let no secret sin lodge within, for that will rot the mind. If you would be kept, bring every dark thing to the light. The heart that harbors a lust, a grudge, a proud rebellion, cannot know the keeping of Christ. He saves from sin, not in sin. Cry mightily, "Save me from its guilt and its power!" and He will make war upon your besetting corruption until you walk in liberty. Your fruit, your sanity, your steadfastness must be found in Him alone, not in your own resolve. The dew from heaven, the sun by day, the very breath you draw, all must whisper, "From me is thy fruit found."
Do not fear evil tidings with a slavish dread. The heart fixed on God's sovereign goodness cannot be shaken, though the earth give way. Yet let there be a holy fear, a watchful trembling lest you stray onto the broad road that runs so near the narrow. The soul that examines itself, that walks humbly, that feels its own emptiness, is safest. Bold presumption is a shipwreck, but holy caution keeps near the harbor. If you cannot lean upon His arm, run after Him like a dog at his master's heels. Follow hard after Him, and He will not leave you to the wolves.
You ask for a right mind, then ask also for a tender conscience, a will bowed to the Lord's command, even if it separates you from all else. The path of wholehearted obedience is the path of peace, though the world frown. And if you would be kept, remember what you were when He found you: naked, poor, miserable, an enemy and afar off. That memory will humble you and hold you fast to the Giver of all grace. Trust Him now. He is yours, and you are His, if you have believed. His finished work is your peace, His intercession your safeguard, His Word your unbreakable shield.