In all circumstances take up the shield of faith, with which you can extinguish all the flaming darts of the evil one; (ESV)
What kind of shield are we talking about? It was not a small shield.
“The shield indicated here . . . was a large shield about four feet high and two and a half feet wide. . . The Roman shield was made of two layers of laminated wood, covered first with linen and then with hide, and then bound top and bottom with iron, with an iron ornament decorating the front of it. A man could put his entire body behind it as it absorbed the javelins and arrows of the enemy. In the case of flaming arrows, very often the arrow would snuff out as it buried itself in the thickness of the shield. During battles these great shields would often bristle with smoking arrows like roasted porcupines.”
- Hughes, R. Kent. Ephesians: The Mystery of the Body of Christ, page 234.
The enemy is firing arrows at us constantly. Let me ask you, do you know where your weaknesses are? If you don’t, I can assure you that the enemy does. Some struggle with lust. Some are tempted by power. Some fall for the arrows of gossip or hypocrisy. Others struggle with pride. For others it is rage and anger. Those arrows are coming fast and furious.
Are you ready with that shield of faith? And that begs the question . . . faith in what?
1 John 5:4
 For everyone who has been born of God overcomes the world. And this is the victory that has overcome the world—our faith.
Our faith in God, revealed to us in his Word. Do you remember the Gospel account where Jesus was led into the desert to be tempted by Satan? How did he defend himself against the arrows of the enemy? He responded with the Word of God every time. “It is written.”
Satan will attack you. He will use his demons. He will even use church members. You need to be ready to raise that shield of faith. Faith in the unchanging truth of God. When you are lied about, attacked, demeaned, or tempted raise that shield. Have faith that God is in control, and will protect you as you look to him.
You need the large shield that faith in God provides. If you compromise on the word of God, your shield won’t be big enough to protect you. Know your weaknesses. Your enemy knows them. Build your faith. Know the Word of God. It will shield you from the fiery darts of the enemy.