13 When tempted, no one should say, “God is tempting me.” For God cannot be tempted by evil, nor does he tempt anyone; 14 but each person is tempted when they are dragged away by their own evil desire and enticed. 15 Then, after desire has conceived, it gives birth to sin; and sin, when it is full-grown, gives birth to death. — James 1:13-15 NIV
When we were born physically, we were born into a sinful world. We live in bodies of flesh that have carnal desires. Because sin is still in the world and we are all infected and affected by it, we follow(ed) after those fleshly, carnal desires. The lifestyles that we live(d) are/were not pleasing to God. Jesus sent His Son to redeem us from this fallen state. When we accept Jesus as our Savior, we are born again spiritually, we become new creations in Christ Jesus. We get a new heart with new desires but, the flesh does not just automatically and instantly give up and die. The old desires are still there and it is a constant, second by second battle to defeat the desires of the flesh. To kill those fleshly desires, we not only need open heart surgery, but we need major brain surgery. Our mindset and our attitudes have to be changed. When carnal, evil, unkind, sinful thoughts “pop up” in our minds, we can be sure that those thoughts do not come from God, but, rather from satan and his minions. We must always remember that they are liars and they are here only to destroy us.
8 Be alert and of sober mind. Your enemy the devil prowls around like a roaring lion looking for someone to devour. — 1 Peter 5:8
We are tempted by these evil thoughts. If we allow ourselves to be enticed and follow those fleshly desires, they lead us to sin and sin eventually leads to death.
But we have a way out, we have a redeemer and a High Priest who has suffered those same temptations and understands our weaknesses. He defeated satan at the cross, so that we could live full, abundant lives.
10 The thief does not come except to steal, and to kill, and to destroy. I have come that they may have life, and that they may have it more abundantly. — John 10:10 NKJV