“Therefore take up the whole armor of God, that you may be able to withstand in the evil day, and having done all, to stand firm.” (Ephesians 6:13 ESV)
Saint Paul did not want us to underestimate the obstacles that stand in the way of living a life that is pleasing to the Lord. These obstacles are often placed in our path by Satan our adversary. He and his minions are so crafty that they know just how to accuse and tempt us and just who to use to do it. He influences his slaves to accomplish his ends. His slaves include those in high places of earthly authority who wreak terrible havoc and inflict violence and terror on all of humanity. He is at his best when he convinces people that he does not exist. Then they think they are in control, exercising their free will. They are not prepared for the devil nor can any resist him. Therefore he has free rein to use his deceitful allurements.
Paul wants believers to always be vigilant and on our guard, thoroughly equipped for the battle at any moment and ever in prayer. We are to put on the spiritual armor of God which Paul likens to the armor of a Roman soldier. We must use this spiritual armor to defend ourselves against the assaults of temptation and doubt. We are also to wage spiritual battle offensively to free souls from the darkness and slavery of sin.
The truth of the gospel must be the foundation for it all. We must be ever mindful that we who are in Christ possess His righteousness by faith and that our salvation is assured. Such assurance will protect us when the devil tries to convince us that we are too evil for God to love us. Paul points out that the boots we wear are the gospel of peace. These signify that we are to be always walking in the peace of God and extending it to all we meet. The offensive weapon we have is the word of God. When we speak it in prayer, preaching, teaching, counsel and conversation, it cuts deeply into the souls of men, revealing and exposing their sins and causing them to repent, to die to self and become alive by faith to Christ.