When in combat, battle, or war, the function of the shield is to defend the soldier or the warrior from being wounded. It is a protective equipment that wards off the attack of the enemy. It defends the one who uses it to keep him from being injured or wounded. The psalmist says that God is the shield of the upright. Uprightness is a matter of the heart and not just the outward appearances and observances. God sees our hearts and He knows those who are His and who have the uprightness of heart through the grace of Jesus Christ who gives us righteousness. “For the LORD sees not as man sees: man looks on the outward appearance, but the LORD looks on the heart.” – 1 Samuel 16:7. He is a shield to His people and He protects them from any attacks of the enemy.