You you use your salvation in spiritual warfare will depend on how victorious you will be. Salvation is a one time event where you embrace the truth about Jesus, believe it, and start applying it to your life. The helmet of salvation is put on every day when you choose to follow Jesus wherever he leads. You use the helmet to protect your mind against Satan's attacks.
You have to be a Christian to be able to have the helmet of salvation. You start to use the helmet in prayer. Your prayer life has a direct correlation on how well the helmet protects your mind. You use prayer when you are in God's Word to build that relationship with God.
Use prayer to discover the strongholds that Satan has over your mind and how to remove them. Use prayer to identify where you are allowing negativity into your heart. Use prayer to know how God wants you to fight in spiritual warfare. Use God's Word to know what God expects from you. Apply God's Word with prayer to know where you need to strengthen your thinking, attitude, and heart resolve to do good instead of evil in the world.
Satan will take advantage of any opportunity he gets to mess with you, so make sure you protect your mind. Take care of your armor to make sure you are being protected. Your value is found in Jesus. No other opinion matters. If you believe Satan's lies, then you cripple yourself, but he doesn't have the power to take you out. Seek God's approval and your mind will be fortified with love, faith, kindness, and mercy. Walk with God and there is no room for insecurities.
Acts 4:8-12, Romans 6:21-25, Ephesians 2:8-10, 6:13-17, & Philippians 2:12-13