What does it mean to guard your heart?
Here's the answer:
Guarding your heart means to protect what you allow to go into your heart.
Healthy food and exercise will keep your physical heart healthy. Just like your physical heart, you’ll want to keep your spiritual heart healthy. This means keeping your heart full of good things. When your heart is filled with good things, you will be a light for Christ. If you fill your heart with bad things, it will show in your life.
Guarding your heart means you do not allow anything bad into it. Gossip, hatred, and lying are examples of things that are bad for your heart. When you guard your heart, you prevent those bad things from getting inside. Instead, you should fill your heart up with good things.
"Above everything else, guard your heart. Everything you do comes from it" (Proverbs 4:23).
"When you look into water, you see a likeness of your face. When you look into your heart, you see what you are really like" (Proverbs 27:19).
"Finally, my brothers and sisters, always think about what is true. Think about what is noble, right and pure. Think about what is lovely and worthy of respect. If anything is excellent or worthy of praise, think about those kinds of things" (Philippians 4:8).