Carnal thinking: I am depressed
Spiritual thinking: The joy of the Lord is my strength
It's really that simple...or is it? 

Knowing the truth is simple but applying it takes wisdom. We know that carnal thinking leads to death and spiritual thinking leads to life and peace (Romans 8:6). The question that should leave you with is this; how do I think spiritually and how does it produce life and peace?

For to be carnally minded is death; but to be spiritually minded is life and peace.

Carnal mindedness isn't necessarily depraved, sinful thinking, carnal thinking in its most basic form just leaves God out. Carnal thinking reasons based on what seems logical according to the way of the world. Spiritual thinking reasons based on God's ways and the fact that God can make a way where there is no way.

Carnal thinking is influenced by what it can see, spiritual thinking realizes there's an unseen element in the equation that can change things. Spiritual thinking realizes that with God, all things are possible. If you are facing a challenge and don't see how God can do anything about it, you're limited to what makes sense carnally and you simply need to repent.