10 Finally, be strong in the Lord and in the strength of his might. 11 Put on the whole armour 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 armour 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."
Ephesians 6:10-18
While on this particular aspect of Paul's teaching, we may begin to see a real significance in the phrase 'the evil day, which commentators think has reference to a time of crisis - 'the dark crisis of the campaign', as Moule puts it, or 'the crisis (as each crisis comes on) of temptation or of terror'. There are ample evidences in Scripture of the sudden onslaughts of the evil one, that bring a sense of crisis in almost an instant of time. One thinks of Peter in the Judgment Hall, when the artless comment of a servant maid plunged him into a morass of fierce and devastating temptation - that was 'the evil day' for him!
Something should be said at this point about the devil himself, the 'diabolos' as he is called in the Greek. Scholars point out that this word is a regular equivalent, though not the precise translation of the Hebrew 'Satan'. In the Greek this word literally means 'Slanderer' or 'Accuser'. The actual word is an adjective but is often used as a noun, and if we wanted to be precise we would have to call him 'the slanderous one', and the heart of his slander is that it is false accusation. Hence, he is called in Revelation 12:10, 'the accuser of the brethren'. This 'false accusation' idea may be what lies behind our Lord's description of him that he is 'a liar, and the father of it' (John 8:44). It is always a good and necessary exercise to examine the Scriptures' reference to Satan's wiles, his voice, and his guises. His voice, for example, is heard only three times in all Scripture - in the garden of Eden, in the story of Job and in the record of our Lord's temptation. Surely that invites us to study these references with great care, and to seek to understand their implications. Similarly, it is important to examine the ways in which he is portrayed. As well as being called the tempter, he is also called 'an angel of light' (2 Corinthians 11:14), 'a roaring lion' (1 Peter 5:8), the 'hinderer' (1 Thessalonians 2:18), 'the destroyer' (1 Corinthians 5:5). All these names have significance and we will be wise to examine them with care (although not in detail at this point, but it may be that we shall find ourselves referring to them in relation to the different parts of the armour in the verses that follow).