Paul has been telling us how to maintain this beautiful mosaic God has put together in Christ. He has one last exhortation: Ephesians 6
10 Finally, be strong in the Lord and in the strength of his might. 11 Put on the whole armor of God, that you may be able to stand against the schemes of the devil. 12 For we do not wrestle against flesh and blood, but against the rulers, against the authorities, against the cosmic powers over this present darkness, against the spiritual forces of evil in the heavenly places. 13 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. 14 Stand therefore, having fastened on the belt of truth, and having put on the breastplate of righteousness, 15 and, as shoes for your feet, having put on the readiness given by the gospel of peace. 16 In all circumstances take up the shield of faith, with which you can extinguish all the flaming darts of the evil one; 17 and take the helmet of salvation, and the sword of the Spirit, which is the word of God, 18 praying at all times in the Spirit, with all prayer and supplication. To that end, keep alert with all perseverance, making supplication for all the saints, 19 and also for me, that words may be given to me in opening my mouth boldly to proclaim the mystery of the gospel, 20 for which I am an ambassador in chains, that I may declare it boldly, as I ought to speak.
The enemy is trying to invade the household - not some physical enemy from outside, but one who works inside. Just like God the Father, and the Son, and their holy angels are able from heaven to see this beautiful mosaic He has brought together, the forces of evil in the heavenly places are looking for weak vantage points where they can attack. Again, this is not physical. They attack with doubts, temptations, discouragements, fears, and lies. Therefore, our preparation for battle must be in the mind and the spirit. We need the truth; we need to keep our relationships with God and His people in order; we need to trust in Christ and God's Promises, and we need to keep our lines of communication with God, through His Son at His right hand, open, because He can see what we cannot see, to protect His wonderful masterpiece.