The breastplate of righteousness protects your spiritual heart and soul. It is what shields you from being destroyed by Satan's attacks. It protects you because righteousness makes you right with God. When you are one of God's children you can trust that He will protect you. If you believe in God's truth, then righteousness is protecting you.
If you are a Christian, then you are righteous. Jesus is the reason you are able to have righteousness. He is what opened the eye to those who wanted to truth to see the need for God. You cannot achieve righteousness without Jesus. It is his righteousness that you receive upon salvation that protects you from becoming legalistic about your faith.
God does not lower His standards. He meets you where you are, but you are expected to change and become more like Jesus as you mature in your faith. The more you understand the truth the easier it becomes to live out your righteousness. This protects your heart from becoming hard or allowing evil to touch it. You may have the ability to take down your enemies, but when you choose to act in love you are justified.
Righteousness protects you from discouragement and deception. It defines who you are in Jesus. This protects you because it makes you innocent. Satan hate innocence and tries to take advantage. That is why you need the protection of righteousness. Jesus has freed you through faith, don't keep living like you are chained to your sin. Live out your Christian life in integrity to honor God for His protection and forgiveness.
Genesis 15:6, 1 Samuel 24:3-21, 1 Kings12:25-33, Isaiah 64:1-7, Romans 3:9-26, 4:20-25, 10:1-4, 2 Corinthians 5:16-17, & Ephesians 6:13-14