How to Wield The Shield of Faith

The vital importance of faith is a central theme in many movies. Is the protagonist going to believe and conquer, no matter how seemingly impossible the odds, or give in to doubt and fail?

Inevitably, faith wins out: the lead character chooses to trust, and all ends well. But what exactly are we supposed to believe in?


That part of the equation is often obscure. Is it faith in ourselves, faith in the power of teamwork, faith in our destiny, or something else? The object of your faith doesn’t seem to matter too much in these movies; what matters is simply that you “keep the faith” and “don’t stop believing.”

As a result of this common cultural emphasis, people sometimes say, “I wish I could believe in Christianity, but I’m afraid I just can’t believe that people rise from the dead. I think it is wonderful that you believe though. I’m glad for you that you have your faith.”

Such people do not understand the biblical concept of faith, however, which is rooted in reality. If there is no solid foundation to faith, then faith itself is worse than useless; it is false and misleading. I may firmly believe that I could yet have a future in professional rugby as a skinny, not particularly fast fifty-six-year-old, but frankly that is never going to happen, nor was it even when I was fifteen.

In biblical terms, faith must always have a firm foundation if it is to be meaningful, or it is simply a glorious falsehood. Faith is not, as the skeptic Ambrose Bierce once defined it, “belief without evidence in what is told by one who speaks without knowledge of things without parallel.”[1]

That is why Paul told the Corinthians, “If in Christ we have hope in this life only, we are of all people most to be pitied” (1 Cor. 15:19). If Jesus Christ’s resurrection is a myth or a fantasy, it is not a charming delusion to be tolerated or encouraged because it enables some people to live happier and more moral lives. Faith in the resurrection is only meaningful if it is actually true.

True biblical faith derives its power not from any power inherent in faith itself but rather from the object of that faith. Faith is merely the instrument that connects us to the utterly trustworthy and all-powerful God, who created the heavens and the earth and who made us for relationship with him.

True biblical faith derives its power not from any power inherent in faith itself but rather from the object of that faith.

This is the faith of which Paul is speaking in our passage when he says, “In all circumstances take up the shield of faith, with which you can extinguish all the flaming darts of the evil one” (Eph. 6:16). He is not saying that faith has some remarkable defensive power against Satan, in and of itself.

Rather, he is saying that faith protects us from Satan’s attacks because of what faith enables us to take hold of, namely, the power and protection of God himself.


This becomes clear when you look at the usage of shield imagery in the Old Testament. Throughout the Old Testament it is not faith but God who is repeatedly described as our shield.

In Genesis 15:1 the Lord tells Abraham, “I am your shield; your reward shall be very great.” Proverbs 30:5 says: “[God] is a shield to those who take refuge in him.” This same theme is repeated many times in the psalms. For example, in Psalm 3:3 David says: “You, O Lord, are a shield about me, my glory, and the lifter of my head.” In Psalm 28:7 we read, “The Lord is my strength and my shield.” In Psalm 119:114 the psalmist says to the Lord, “You are my hiding place and my shield.”

Perhaps the closest parallel to our passage in Ephesians 6, however, is Psalm 91. This psalm deals with a believer who finds himself under attack from warfare, plague, pestilence, and the arrows of his enemies. Many commentators have discerned a spiritual dimension to the assaults described in this psalm. The psalmist affirms that in the midst of that all-encompassing assault, he will be safe:

He will deliver you from the snare of the fowler
and from the deadly pestilence.
He will cover you with his pinions,
and under his wings you will find refuge;
his faithfulness is a shield and buckler.
You will not fear the terror of the night,
nor the arrow that flies by day,
nor the pestilence that stalks in darkness,
nor the destruction that wastes at noonday. (Ps. 91:3–6)

God himself is our shield; he is our refuge; he is our hiding place in the day of difficulty; his faithfulness will keep us safe when we are being shot at by arrows, flaming or otherwise.


But if the Old Testament tells us that God is our shield, why does Paul say that faith is our shield? Faith is the means by which we flee to God for refuge. It is how we cling to God and find in him comfort and protection in times of difficulty and distress.

Imagine you have fallen into the sea and are drowning. You can’t swim, and there is nothing you can do to save yourself. But then somebody throws you a rope. If you grab hold of that rope, you can be pulled to safety, but in order to be saved, several things are necessary.

First, you need to believe in the existence of the rope and that there is someone at the other end of it. If there is no rope, there is nothing to grab. If there is no one at the other end of the rope, there would equally be no point in grabbing it.

But it’s not enough to believe in the existence of the rope and of someone at the other end of the rope; you also need to be convinced the person at the other end of the rope wants to help you. If it were wartime, and the person at the other end of the rope were an enemy, there might be no point in grabbing the rope, because the enemy might shoot you anyway. But if the person on the other end of the rope were your best friend, you would confidently grab the rope.

If all your beliefs don’t lead you to the necessary action, then they won’t do you any good.

Yet you could believe all these things and still drown if you didn’t actually grab the rope. If all your beliefs don’t lead you to the necessary action, then they won’t do you any good.

This picture helps us understand what Christians mean when they talk about faith. Faith is not simply saying, “I believe in God.” Such a generic belief in a supreme being is not what Paul means. He is talking about faith in the specific God who loved the world so much that he gave his only Son so that we should not perish but have everlasting life.

Yet even when we are able to define faith in biblical terms, we might have to confess that our faith isn’t the shield it should be against the flaming arrows of the enemy.


Our beliefs aren’t always a consoling and sustaining reality in the midst of the greatest stresses and trials of life. Maybe you are bent over in the midst of a spiritual or emotional hurricane, and your faith is not acting as a shield for you right now. At the time you most need it, you feel unable to take up the shield of faith and use it as God intended.

Why isn’t your faith a shield for you in the midst of the storm? Well, to throw you back into the sea for a moment, the simple belief that there is somebody at the other end of the rope is not enough.

It is not enough to believe that there is a God somewhere out there. You have to know he has the power to deliver you—to pull you in, if you like. For faith to be your shield, you need to believe that God is sovereign over every detail of the universe. You must know that your God directs not only the affairs of men and nations but ordains the car crash, the job layoff, the health challenges, the relational difficulties.

Each of these things comes into our life because God, the supreme commander of the universe, has dictated it to be so. This is where our functional unbelief is so often a problem. We may confess in theory the doctrine of God’s sovereignty, but we have a hard time holding on to that truth in the desperately difficult challenges of life in a fallen world, where the powers of evil around us often seem very strong, and our world seems totally out of control.

To experience faith as a shield, you need to know not only that God is powerful but that this God is your friend. God’s sovereignty is not in the least comforting unless you know that this sovereign God is on your side. Here, too, we often struggle. In the midst of the intense pain of life, we find it hard to believe that God is really on our side.

Perhaps you have prayed to God desperately and nothing has happened. The doubts easily creep in. Your belief in God won’t shield you if you don’t believe God is for you.

[1] Ambrose Bierce, The Devil’s Dictionary (New York: Sagamore Press, 1957).

Content taken from The Whole Armor of God by Iain M. Duguid, ©2019. Used by permission of Crossway, a publishing ministry of Good News Publishers, Wheaton, Il 60187,

Iain M. Duguid (PhD, University of Cambridge) is professor of Old Testament and dean of online learning at Westminster Theological Seminary and the pastor of Christ Presbyterian Church in Glenside, Pennsylvania. He has also served as a missionary in Liberia, taught at Westminster Seminary California and Grove City College, and planted churches in Pennsylvania, California, and England.