Our last piece of protective armor is a helmet called salvation. Before we answer why we need this helmet, we first must understand salvation. The Bible, God’s holy word, tells us sometime after the seven days of creation, the serpent deceived Eve, so she disobeyed God and ate the forbidden fruit. Eve then gave the fruit to Adam and he chose to disobey. With this sin or act of disobedience, a sin nature came to everyone born from Adam. Now all have sinned and fallen short of God’s glory and as God told Adam before He created Eve, the penalty would be death. This was not just physical death, but spiritual death or complete and eternal separation from God.
However, because God so loved the world, prior to creation He had a plan in place to rescue mankind. Since the penalty of death or law was set in stone, any rescue would involve death. God’s plan: A onetime substitute would die in our place. However, the blood spilt in this death could not be tainted with sin – it had to be sinless. But there was no one. Therefore, God's own arm brought salvation.
Our Eternal, Triune or Three-in-One God is Spirit and He cannot die. So, how could He save us? The only way was to create for Himself a human body and be our Sinless Substitute. This is exactly what He did. God the Father sent Jesus, God the Son, into the world to pay the penalty of our sin, to shed the blood required for forgiveness and die on a cross in our place. Jesus, born of a virgin so sinless blood flowed through His veins, is our Substitute, the onetime sacrifice satisfying the law set in stone.
Nevertheless, this is not automatic salvation. Jesus paid the penalty, but we have to make a choice. Do we choose Jesus as our Substitute, or pay the penalty of death ourselves? These are our choices. If we choose to pay it ourselves, the Bible tells us our fate is eternal separation from God in the Lake of Fire. But, if we choose Jesus, He gives the gift of eternal life in heaven.