You should control your thoughts. This will not be an easy task; you cannot accomplish it without close and even severe effort. Yet God requires this of you; it is a duty resting upon every accountable being. You are responsible to God for your thoughts. If you indulge in vain imaginations, permitting your mind to dwell upon impure subjects, you are, in a degree, as guilty before God as if your thoughts were carried into action. All that prevents the action is the lack of opportunity. Day and night dreaming and castle-building are bad and exceedingly dangerous habits. When once established, it is next to impossible to break up such habits, and direct the thoughts to pure, holy, elevated themes. 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. You are weak in this direction. (2T 561.1) MC VC

You have become wayward, bold, and daring. The grace of God has no place in your heart. In the strength of God alone can you bring yourself where you can be a recipient of His grace, an instrument of righteousness. Not only does God require you to control your thoughts, but also your passions and affections. Your salvation depends upon your governing yourself in these things. Passion and affection are powerful agents. If misapplied, if set in operation through wrong motives, if misplaced, they are powerful to accomplish your ruin and leave you a miserable wreck, without God and without hope. (2T 561.2) MC VC