Romans 7:25 states, “Thanks be to God—through Jesus Christ our Lord! So then, I myself in my mind am a slave to God’s law, but in the sinful nature a slave to the law of sin.” Our minds are the key to the Spirit filled life of victory. This is true because the spiritual battle wages most intensely in our thought life. Our thoughts either reinforce our pursuit of godliness or they lead us to follow our sinful desires. Romans 8:5-7 says:
⁵Those who live according to the sinful nature have their minds set on what that nature desires; but those who live in accordance with the Spirit have their minds set on what the Spirit desires. ⁶The mind of sinful man is death, but the mind controlled by the Spirit is life and peace; ⁷the sinful mind is hostile to God. It does not submit to God’s law, nor can it do so.
Notice the emphasis on the mind. What we allow to occupy our minds inevitably gets expressed through our words and our actions. Picture it this way: Suppose you are on a camping trip with some friends. There is no purified water so you need to boil water to drink.  You set up your Coleman stove, light the gas and put on a pot of water.  Pretty soon the water boils and steam rises out from the pot. Let’s say, for the sake of argument, you don’t want any steam to escape from the pot…you find a lid and put it on top of the boiling water. This works for awhile but as the pressure builds in the pot, steam inevitably escapes. You can try to find a heavier lid but what else could you do to stop steam from coming out of the pot? That’s right, turn off the heat!  Here’s the analogy; the fire represents our thoughts, the water represents our emotions and the steam represents our actions.  The fire of our thoughts boils the water of our emotions which produces the steam of our actions. What we think about captures our feelings and influences our behavior.  There is an inseparable relationship between our thoughts, our feelings and our actions. 
Lasting spiritual change happens when we have renewed minds. Romans 12:2 asserts, “Stop being conformed to this world, but be transformed by the renewing of your mind…” We renew our minds when we surrender our thoughts to the Holy Spirit’s control and we meditate on God’s truth. Colossians 3:2 exhorts us, “Set your minds on the things above, not on the things that are on earth.”
Here are practical applications:

1. Begin every day with a prayer of surrendering your mind to the Spirit’s control. Ask Him to fill your thoughts and your life (Luke 11:13, Romans 8:5-7)
2. Take some time every day to read God’s Word. As you read the Scriptures, ask God to speak to you and fill you with His thoughts (1 Cor. 2:10-16, Joshua 1:8)
3. Discipline yourself to hide God’s Word in your hearts by regularly memorizing Scripture. Begin with Romans 8:1-17. Take one or two verses a week, memorize it and daily speak it to yourself and to God (Psalm 119:9-11, Matthew 4:1-11)

 
“Therefore, gird your minds for action, keep sober in spirit, fix your hope completely on the grace to be brought to you at the revelation of Jesus Christ.” (1 Peter 1:13)