“O how love I thy law! it is my meditation all the day.” -Psalm 119:97.
Daydreams & imaginations come from idle minds, and we must strive to submit even these to the Lordship of Jesus in our lives. When our thoughts wander without purpose, it tends to give place to the evil desires of our hearts; that very sinful nature each of us has, the one we wrestle against as Christians all of our lives.
Jesus said that we are not corrupted by external things, but what proceeds from the heart within defiles us, and those evils come forth from our thoughts, or imaginations. So then our evil inclination toward sin comes from the heart, but our minds fashion the plans to carry out that desire; and the heart acts upon us as a deceiver, convincing the mind to act.
“And GOD saw that the wickedness of man was great in the earth, and that every imagination of the thoughts of his heart was only evil continually.” -Genesis 6:5.
“...for the imagination of man’s heart is evil from his youth;” -Genesis 8:21B.
“The heart is deceitful above all things, and desperately wicked: who can know it?” -Jeremiah 17:9.
“And he said, That which cometh out of the man, that defileth the man. For from within, out of the heart of men, proceed evil thoughts, adulteries, fornications, murders, Thefts, covetousness, wickedness, deceit, lasciviousness, an evil eye, blasphemy, pride, foolishness: All these evil things come from within, and defile the man.” -Mark 7:20-23.
It is imperative that we learn to give God the control of our thoughts, and of course it will be something we need to do repeatedly. Please remember that in turning things over to God, it is not a measure of your own will power (Psalm 33:16-18)! We rely on God's power & grace by Jesus His Son (Romans 5:8-10), and the gift of the Holy Spirit (I John 4:13) within us. This “battle of thought” is a matter of determined choice for us, but we are reliant upon God's ability to step in and enable us to win. Please take these next verses seriously, and employ them, knowing that the Lord's power within you will overcome bad and persistent thoughts;
“For though we walk in the flesh, we do not war after the flesh: (For the weapons of our warfare are not carnal, but mighty through God to the pulling down of strong holds;) Casting down imaginations, and every high thing that exalteth itself against the knowledge of God, and bringing into captivity every thought to the obedience of Christ;” -2 Corinthians 10:3-5. Bold type added for emphasis.
Getting victory in our thoughts will be a life-long challenge, but we can increase success by staying alert, and changing behavior. First, we have already said that when we are idle, our minds will wander. I am not suggesting just blindly keeping busy, but seeking the Lord for specific direction when the thought struggle comes along. Activities could be prayer (I Thessalonians 5:17), Bible study (Deuteronomy 6:4-9), singing and praise (Ephesians 5:19), small tasks at home, or even visiting someone in need (Matthew 25:39,40).
Second, we need to watch the company we keep (I Corinthians 15:33). Such exposure will greatly affect our minds, and we need to pull away from excessive bad influence. Third, we should avoid bad habits that lend to errant thoughts; television would be near the top of this list, and surfing the internet pointlessly can also misdirect our minds (I John2:15,16). Fourth, we should watch our own conversation, and steer away from negativity. Yes, many times we must deal with hurtful things, but we should steer away when our own considerations of such become excessively discouraging. At this point we can “turn” our direction by considering the good things (Philippians 4:8) God has done for us, and by thoughts of such we'll find courage for the future (Psalm 78:4).
Our minds are incredible things, made in the image of the God whom we love. Steering our minds in the right path takes discipline, and the Lord will grant you that by His precious Holy Spirit which He gives to His children. Victory or defeat in Godly living comes from within us, so let us pray that God will guide our thoughts aright, and keep us from the sinful desires of the heart. We must learn to redeem the time, for indeed these days are evil (Ephesian 5:16).
“Blessed is the man that walketh not in the counsel of the ungodly, nor standeth in the way of sinners, nor sitteth in the seat of the scornful. But his delight is in the law of the LORD; and in his law doth he meditate day and night.” -Psalm 1:1,2.