That is why you must take up all God's armour, or you will not be able to put up any resistance on the evil day, or stand your ground even though you exert yourselves to the full. So stand your ground, with truth a belt round your waist, and uprightness a breastplate,wearing for shoes on your feet the eagerness to spread the gospel of peace and always carrying the shield of faith so that you can use it to quench the burning arrows of the Evil One. And then you must take salvation as your helmet and the sword of the Spirit, that is, the word of God.
Eph. 6:13-17
Dear Brothers and Sisters in Christ
as we all know, the Christian is a soldier or, better, a fighter for Christ. His weapons are not worldly, but spiritual. In an exorcism that precedes the sacrament of baptism in the Orthodox rite of baptism, the priest says: " Begone, and depart from this sealed, newly enlisted warrior of Christ our God!". This is followed by the so-called "Satan renunciations". The dialogue follows: "Do you unite yourself to Christ?". And the baptized person answers: "I do unite myself to Christ!".
Promises made to God at baptism must be kept for a lifetime. Saint Simeon, the New Theologian (10th century), says that we are Christians only to the extent that we keep alive the baptismal grace that dwells in us, renouncing Satan and all his works and uniting ourselves more and more to Christ.
Every grace received from God requires interaction with Him - Orthodox theology speaks here of synergy. Otherwise, the grace received becomes a reason for judgment. The great theologian and martyr Dietrich Bonhoeffer also speaks of a grace 'at a high price' that must be repaid with huge efforts for Christ.
He who goes into combat no longer takes care of the everyday tasks, to please his Lord who has enlisted him (see 2 Tim 2:4). The spiritual armour of the Christian is described by the holy Apostle Paul in the quoted passage from Ephesians, as follows:
Belt your waist with truth. The Christian is a man of truth: “Let us run with perseverance the race that is set before us, looking to Jesus, the pioneer and perfecter of faith” (Col 3:9).
The Holy Spirit is also the Spirit of truth (cf. John 14:17).
The breastplate of righteousness. Righteousness, or justice, in the Christian sense is not just an abstract legal principle. It is a virtue with which the Christian fulfils his duties towards God and his neighbour. A righteous person is severe towards himself, respects the rights of every human being and also forgives the faults of his neighbour.
Lace up your sandals in preparation for the gospel of peace: always be ready to announce the Gospel of peace. "How beautiful upon the mountains are the feet of the messenger who announces peace, who brings good news, who announces salvation” (Isaiah 52:7). Nothing is more precious than peace between peoples and nations, which originates in the heart of every person. And the venerable Seraphim of Sarov (†1833) says: "Acquire the Spirit of Peace and a thousand souls around you will be saved". And peace of heart is acquired with much prayer and asceticism.
The shield of faith. By faith we overcome all temptations that come to us from the devil, the flesh, and the world. " Who is it who conquers the world but the one who believes that Jesus is the Son of God?". (1 John 5:5). Faith is the power of God in us. Without faith, man is spiritually dead and understands nothing of the mysteries of life.
The helmet of salvation is the unwavering hope and certainty that God is with us always, to the end of the age (see. Mt 28:20). And "if God is for us, who is against us?” (Rom. 8:31). The true Christian never loses hope in salvation, and courage in the fight against sin, against the evil and the wickedness of this world.
The sword of the Spirit is the Word of God. With the Word of God, we can discern spirits and preserve ourselves from sin and all temptations in life. The psalmist David says: "Your word is a lamp to my feet and a light to my path." (Psalm 119:105). And the holy abbot and desert father Anthony, the father of monasticism, gives us the spiritual advice: “Have a scriptural witness from the Bible for everything you do”. The Spiritual Fathers thus guide us to always read the Word of God in Holy Scripture, which can inspire us at every moment of our lives, especially when we are at a crossroads, and have to make a decision.