"For though we walk in the flesh, we do not war according to the flesh. For the weapons of our warfare are not carnal but mighty in God for pulling down strongholds, casting down arguments and every high thing that exalts itself against the knowledge of God, bringing every thought into captivity to the obedience of Christ, and being ready to punish all disobedience when your obedience is fulfilled." (2 Cor. 10:3-6)

Please notice that Paul uses the word "weapon" in the plural (not "weapon," but "weapons"). Thus, the Christian has, not just one, but numerous weapons at his disposal in his spiritual warfare. Some of those weapons are: prayer, love, truth, example, etc. Please notice also that the Christian's main battle begins, and should end, in his own mind; e.g., "bringing every thought into captivity to the obedience of Christ." Jesus said, "What comes out of a man, that defiles a man. For from within, out of the heart of men, proceed evil thoughts, adulteries, fornications, murders, thefts, covetousness, wickedness, deceit, lewdness, an evil eye, blasphemy, pride, foolishness. All these evil things come from within and defile a man." (Mark 7:20-21)

Let us keep our hearts with all diligence for out of it are the issues of life. (Prov. 4:23)