God speaks of the warfare in which all Christians are engaged. More than that, there are different kinds of battles mentioned. There are in fact two battles or fronts that every Christians is fighting simultaneously.
First, in passages such as Ephesians 6:10 ff., Romans 7:4 and 1 Peter 2:11 we are made aware of the internal warfare in which we fight against temptation and the whiles of the devil. This is our struggle against sin in the flesh. Like soldiers, we must strive to understand the various pieces of our armor and learn how to use them effectively. God gives us all that we need to be armed and ready for Satan’s attacks, but if we neglect our training, we will be caught off guard.
In 2 Cor. 10, Paul reveals that there is also an external battle that we face. There were some in the church at Corinth who were haughty and exalting themselves above the doctrine of Christ. Therefore, Paul described himself and those with him as needing to come to Corinth with weapons that are “mighty in God for pulling down strongholds, casting down arguments and every high things that exalts itself against the knowledge of God” (vs. 4-5). This is our battle against error.
Such imagery should impress upon us the urgency of our purpose as God’s people. Some may try to ignore the battle. Doing so will not make it go away. We can either face the battle armed and prepared, or unarmed and defenseless. Which do you choose?