In the context of this chapter it is clear that Faith is at war with the Carnal Mind.   

The Carnal Mind is enmity against God.   - Romans 8:7 .   This means that the Carnal Mind is "actively opposed or hostile" toward God.   

Why?   Because God operates in the Faith realm while the Carnal Mind operates in the Sight realm.   - Hebrews 11:6 , 2 Corinthians 5:7

Since there is a conflict we must choose a side - Faith or Sight ; Life or Death.   

But just because we choose Faith does not mean the battle is over.   

The battle is only won when we allow our Minds to be Transformed from Carnal to Spiritual.   Romans 8:6 , Romans 12:2

How is our Mind Transformed ?   

1.   By an act of our Will
2.   By the Word
3.   By the HolySpirit
4.   By exercise.   

We must want our Mind Transformed.   If we do not it will not happen and we will Live our Lives Dominated by Carnal thinking.   We will Live defeated Lives.   

Remember, God does not force us to do anything.   He presents us with choices.   Do you want your Mind Transformed ?   

If we really want our Minds Transformed we must immerse ourselves in the Word of God.   - Ephesians 5:26

To become saturated in the Word we must read it ourselves and Meditate on it.   - Psalm 1:2

To expedite being immersed in the Word listen to teachers and preachers of the True Gospel.   - Galatians 1:8

While we are being washed in the Word , we should Pray in the Spirit.   Doing so builds up our most Holy Faith.   - Jude 1:20

The HolySpirit is our teacher.   He gives us Understanding of Spiritual Truth.   - John 14:26 , Ephesians 1:18

Up to this point all we have done is prepare ourselves for a Transformed Mind.   

In order for the Transformed Mind to Manifest , it must Manifest.   

Wow!   That is profound!   

How do we Manifest our Carnal Mind ?   

We think about Carnal things and then we talk about those Carnal things and we do those Carnal things.   

When we think, say or act Carnally we don't always do it perfectly do we?   No!   But we don't let that stop us.   

Likewise, we must exercise our Transformed Spiritual Mind in order for us to develop skill.   - 1 Timothy 4:7 , Hebrews 5:14 , Hebrews 12:11

We exercise by thinking , speaking and acting from the direction of the Transformed Mind.   

By exercising the Transformed Mind we begin to supernaturally think, talk and act in the Spirit just as we are commanded.   - Galatians 5:16

Only the Spirit can Walk by Faith.   The Carnal Mind walks by Sight.    2 Corinthians 5:7

So, by desiring our Minds be Transformed , immersing ourselves in the Word , Praying in the Spirit and exercising the Word of God in our thoughts, speech and actions our Minds are Transformed .   

At this point we have won the Faith battle.   

The benefits to us and to others when we win this battle are enormous, unfathomable!   - Mark 11:23,24 , Mark 16:17 , Hebrews 4:3

But does this mean our Faith will never be challenged?   No.   But because the battle is won, no Unbelief can appear!