We wrestle not against flesh and blood, but against principalities, against powers, against the rulers of the darkness of this world, against spiritual wickedness in high places. Wherefore take unto you the whole armour of God, that ye may be able to withstand in the evil day…
WILLIAM GURNALL (1617-1679): What is this evil day? Some take this “evil day” to comprehend the whole life of the Christian here below in this vale of tears, and then the argument runs thus: Take to yourselves the whole armour of God, that you may be able to persevere to the end of your life, which you will find, as it were one continued day of trouble and trial. Thus Jacob draws a black line over his whole life—“few and evil have the days of the years of my life been,” Genesis 47:9…Others take the phrase in a more restricted sense, to denote those particular seasons of our life wherein more especially we meet with afflictions and sufferings.
MATTHEW POOLE (1624-1679): In the evil day. Times of temptation, and Satan’s greatest rage: See Ephesians chapter 5, verse 16: Redeeming the time, because the days are evil―either wicked, by reason of the wickedness of those that live in them, or troublesome, full of difficulties and dangers, by reason of men’s hatred of you.
WILLIAM ARNOT (1808-1875): It was an evil day for the nation when rulers began to ignore the Bible, and govern as if God had never spoken to men.
WILLIAM GURNALL: But what is this evil day?
MARTYN LLOYD-JONES (1899-1981): What does the apostle mean by the evil day? The “evil day” means a Satanic attack.
WILLIAM GURNALL: This is the season when the evil one, Satan, comes to tempt.
MARTYN LLOYD-JONES: There are days in the lives of Christian people when hell is, as it were, let loose, when the devil seems to marshal all his forces against us from all directions. It is something unusual and exceptional―but let us not forget it. The greatest saints have given descriptions of these evil days, when the devil, having failed to catch them along the usual lines, made an unusual effort so that they were not given a moment’s peace. It might go on for weeks with scarcely any intermission at all. The evil day!
A. W. PINK (1886-1952): I passed through a very trying season in December  which shook me to my foundations. The Lord seemed to give Satan the full length of his rope towards me.
C. H. SPURGEON (1834-1892): I speak what I do know [by experience], and not what I have learned by report, when I say that there is a chamber in the experience of some men where the temptations of the devil exceed all belief. Read John Bunyan’s Grace Abounding, if you would understand what I mean―John Bunyan could not have written as he did if he had not been dragged about by the devil for many years.
MARTIN LUTHER (1483-1546): David must have been plagued by a very fearful devil. He couldn’t have had such profound insights if he had not experienced great assaults.
ARCHIBALD ALEXANDER (1772-1851): Some people make a mock of Satan’s temptations, as though they were the dreams of superstitious souls. Not so Paul, and Peter, and John—not so Luther, and Calvin, and Zwingli. Not so any who understand the nature of spiritual warfare.
JOHN CALVIN (1509-1564): In our lives we must always be ready to meet many temptations. For the devil is our perpetual enemy, if we are members of our Lord Jesus Christ. There will be, then, open war without ending and without ceasing.
MARTIN LUTHER: I can tell you that in…idle solitude there are a thousand battles with Satan. It is much easier to fight against the incarnate devil—that is, against men—than against spiritual wickedness in the heavenly places. Often I fall and am lifted up again by God’s right hand…He does not know the meaning of hope who was never subject to temptations.
MARTYN LLOYD-JONES: [In 1949] I was brought to the end of myself in a way that had never happened before. I really saw the depths of sin and that man’s ultimate problem is his pride…In my opinion, God wanted to do something new to me, so He gave the devil liberty to attack like he did with Job. That was a real Satanic attack and the devil would get me right down but then God would lift me up. So the two went together. That is most important.
JOHN CALVIN: Let us defy the devil, because we are in the protection of our God, who is of invincible power, and because our Lord Jesus Christ has taken upon Him the charge of our salvation and promised to be a faithful keeper of our souls to the end. When we are once at that point, then we shall beat back the darts of the devil. For on the one hand he will labour to make us distrust God’s grace, and on the other hand, he will make us believe that our Lord Jesus Christ is far from us, and even tempt us to murmur against Him, or to raise trifling and unprofitable questions, or else blasphemies, and similar things. And these are the darts.
C. H. SPURGEON: Christian, dost thou think that Satan will let thee alone? No, he will be always at thee, for he “goeth about like a roaring lion, seeking whom he may devour.” Expect trouble, therefore, Christian—but despond not on account of it, for God is with thee to help thee and to strengthen thee.