The book of Judges, in chapter 7, records a fascinating account of the Lord leading an army of 300 men with Gideon as their leader, against the Midianite army whose number is likened to be like that of the sands of the sea (Judges 7:7,12). Interestingly, instead of arming the men with weapons of warfare, Gideon gives to each man, to hold in his hand a pitcher with a lamp within and a trumpet. Upon reaching the vicinity of the enemy camp, the trumpets are sounded, the pitchers are broken and each man holds in his left hand a lamp and in his right the trumpet to blow proclaiming, the sword of the Lord, and victory in won.
As an earthern vessel (pitcher) (2 Corinthians 4:7), we have in us, the Light (lamp) of the world, Jesus Christ (John 9:5). Just as the pitchers were broken, we must be broken (put on the mind of humility) so that the Light of the world, shall shine forth over the darkness of sin and death. We must also take in our hands, the trumpet to sound and proclaim the sword of the Lord, which is the word of God (Ephesians 6:17). In other words, we must be vocal of our faith in Jesus Christ.
For victory in the war that happens in heavenly realms, we must have Jesus Christ (lamp) in us (pitchers) and not be afraid to proclaim Him with booming (trumpet) sound.