Stand therefore, having fastened on the belt of truth, (ESV)
Truth is perfect. If truth has even a shred of falsehood it is not the truth. The danger that we face in our current culture is that people have a notion that truth is not perfect. People will say, "You have your truth. I have mine." This flies in the face of reality, as well as the written Word of God.
“Once, when a stubborn disputer seemed unconvinced, Lincoln said, "Well, let's see how many legs has a cow?"
"Four, of course," came the reply disgustedly.
"That's right," agreed Lincoln. "Now suppose you call the cow's tail a leg; how many legs would the cow have?"
"Why, five, of course," was the confident reply.
"Now, that's where you're wrong," said Lincoln. "Calling a cow's tail a leg doesn't make it a leg."
- Bits and Pieces, July, 1991.
Truth is perfect. And Paul uses the illustration of a girdle of truth that will hold us together in the battle. R. Kent Hughes writes the following:
“When a soldier tightened his belt he was ready for combat, because in the process of tightening he drew up his tunic and cinched it so it could not impede him as he charged into battle. It also firmly fixed his sword in place. . . His belt held everything in place. Without it, he would be powerless in battle.”
- Hughes, R. Kent. Ephesians: The Mystery of the Body of Christ, Crossway Books, page 224.
When you are held together by the perfect Word of God, you will have a piece of armor that is working for your victory! That word of God will hold your life together when your world is falling apart. But, if you allow yourself to accept half truths or distortions of the truth, none of the rest of the armor will do you a bit of good.
“Once the Devil was walking along with one of his demons. They saw a man ahead of them pick up something shiny. "What did he find?" asked the demon.
"A piece of the truth," the Devil replied.
"Doesn't it bother you that he found a piece of the truth?" asked the demon.
"No," said the Devil, "I will see to it that he makes a religion out of it."
- Klyne Snodgrass, Between Two Truths - Living with Biblical Tensions, 1990, Zondervan Publishing House, p. 35.
 Sanctify them in the truth; your word is truth.
2 Timothy 3:16-17
 All Scripture is breathed out by God and profitable for teaching, for reproof, for correction, and for training in righteousness,  that the man of God may be complete, equipped for every good work.
God’s Word is perfect. It is breathed by God himself. May his perfect truth be what holds your life together. No matter the spiritual battle. May you be held together by God’s perfect truth.