For the desires of the flesh are against the Spirit, and the desires of the Spirit are against the flesh, for these are opposed to each other, to keep you from doing the things you want to do. – Galatians 5:17

There is a civil war happening within every Christian every day.  That is the battle between the flesh and the spirit.   In our decision making, we face the pull from opposite forces that lead to opposite outcomes.  It’s only when you decide to walk in the spirit that you are able to are walking as a mature Christian and not a carnal Christian.

But I, brothers, could not address you as spiritual people, but as people of the flesh, as infants in Christ. I fed you with milk, not solid food, for you were not ready for it. And even now you are not yet ready, for you are still of the flesh. For while there is jealousy and strife among you, are you not of the flesh and behaving only in a human way? For when one says, “I follow Paul,” and another, “I follow Apollos,” are you not being merely human? – 1 Corinthians 3:1-4

Milk refers to the gospel message and the ABCs of faith. Solid food refers to spiritual discernment in the use of Gods word.  The Corinthians that Paul was writing to here were saved but they did not grow up to where they should be.  Without spiritual growth, believers will continue to live as they did before Christ.  They will operate with a worldly perspective rather than a Godly perspective, thus not truly living up to their God given potential.

Those who belong to Christ Jesus have nailed the passions and desires of their sinful nature to his cross and crucified them there. – Galatians 5:24

This verse says that as believers, we have crucified our carnal worldly ways on the cross.  Those ways of thinking and acting are dead.

So prepare your minds for action and exercise self-control. Put all your hope in the gracious salvation that will come to you when Jesus Christ is revealed to the world. So you must live as God’s obedient children. Don’t slip back into your old ways of living to satisfy your own desires. You didn’t know any better then. – 1 Peter 1:13-14

This verse is encouraging us to have our minds ready by ensuring that we meditate on the Word of God.  By doing this the desires of our past will be a very faint memory and not strong enough to dictate what we do or how we think.   This verse also give us a warning not to slip back into an old way of living before we knew Christ.

You have been believers so long now that you ought to be teaching others. Instead, you need someone to teach you again the basic things about God’s word. You are like babies who need milk and cannot eat solid food. For someone who lives on milk is still an infant and doesn’t know how to do what is right. Solid food is for those who are mature, who through training have the skill to recognize the difference between right and wrong. – Hebrews 5:12-14

There is something wrong with a grown 30 year old person still eating baby food.  This is the same thing that this verse is saying about out spiritual growth.  When we are a new Christians, it’s ok to be taught the simple things of the gospel.  Actually those things are necessary at that stage.  But as we grow and years pass, we should not only progress to learn about the deeper things found in the word of God, but we should also be in a position to teach what we know to others.

Don’t copy the behavior and customs of this world, but let God transform you into a new person by changing the way you think. Then you will learn to know God’s will for you, which is good and pleasing and perfect. – Romans 12:2

When are try to imitate what the world does we end up living a life or carnality. What this verse is saying to do is read the word of God every day and allow it to transform how we think and act.  When this happens then we will be able to discern what Gods will for our life is.  As long as we are confirming to the ways of this world, we will miss what God really wants us to do with our lives.  And this is sad because as Christians we need to know what God wants us to do so that we can live a truly fulfilling life. Otherwise we would be living a carnal Christian life and that is live having a million dollars in the bank but not knowing the PIN number for your debit card to make a withdraw.  

We demolish arguments and every pretension that sets itself up against the knowledge of God, and we take captive every thought to make it obedient to Christ. – 2 Corinthians 10:5

A mature Christian should be able to do this effectively.  We should be able to recognize when there are thoughts roaming around in our minds that don’t line up with the Word of God. When we recognize this, we are to take them captive and not allow them to cause trouble in our minds.