You are an amazing creature created by God. There is more to you than a single thought, action, or moment. You are multi-faceted in everything about you. So there is no way only one defense system can work for you.
Let me rephrase the above: you are heart, body, soul, and mind and each of these areas needs protection.
Are you familiar with the story of Nehemiah? I'm a little bit in love with this story. A man who has lived his entire life in exile due to the nation he serves is heartbroken when he hears what has happened to the land of his fathers, his homeland. While many went back to rebuild the temple, the city walls were not up and thus the area, the people, the temple, and everything that remained of Jerusalem was defenseless.
Nehemiah spent months in prayer before talking to the King about his plans. He had been put in such a position that this conversation was able to happen, and the King trusted Nehemiah so much he gave his permission. Nehemiah was allowed to return to Jerusalem to fix the walls.
While the story goes on from there regarding his preparations and how he acted, my heart recognized something similar in the first part of the story. God has placed within me a desire to help others be safe. I want to build walls around you, as Nehemiah rebuilt around the city. Of course, I can't do that; not as Nehemiah did. There is no lumber yard, no trees which can be felled, no iron bars which can be strong enough, for me to use to build those walls. But I know my God is able.
What needs to be realized is all the parts of you are connected in ways which can't be divided. Even if you try to compartmentalize your life, there will be run over. What you think will affect how you behave. What you believe about God will affect how you see yourself. What you know about protecting your body, will affect the other aspects of your life. Because that's how we are made. If I only find my worth in pleasing other people, I will put myself in precarious situations, which can endanger my life. It can also affect my soul for I'm not focusing on God but on people who are finicky and indifferent.
Sometimes we are quick to see the need to protect our souls and hearts, though the heart is often hurt by those we love the most. We will be wary about what others try to teach us. Often we think defending our body is not as important. I want you to know they are all important. Every aspect of who you are is important. And while we will never be perfectly safe in this world, we are overcomers and there are ways to live safer.
As Nehemiah realized the wall around Jerusalem needed to be rebuilt, I've realized the wall around ourselves need to be rebuilt. Not to isolate, but to move through this world with wisdom and wariness. Without those protections in place we can't fully be who our God created us to be. It's time to start building.