Here within this Psalm are some amazing promises from God when we are willing to follow and listen to Him. God is telling us here that He will give us everything we need for life. This is one reason Jesus encourages us to “not worry about our lives, what we will eat or drink, what we will wear, or how much we have… because our Father in heaven knows what we need and when we follow Him He will provide for us.” (Matthew 6:25-27)
I once read an article by a shepherd describing his relationship with his sheep. He wrote that there are four requirements if sheep are to peacefully lie down. First they must be free of fear. Then they must be free of conflict with other sheep. Third, they must not be threatened by another wild animal. Finally, they need to be free from hunger.
God is giving us a promise here that as we follow Him as our shepherd, He will take care of these same things. When we follow Him we can be released of all anxiety and fear. When we follow Him we can become more like Christ and be peacemakers instead of being embroiled in conflict. When we follow Him we can be protected from the evil one and his influence in our lives. When we follow Him we have a promise that everything we need will be provided.
But the key to all of this is that we are following and listening. That is why Jesus on so many occasions exhorts us in the gospel, "follow me" and "he who has ears to hear hear." When Jesus is our shepherd, we find for our souls peace and protection and even in the valley the promise of redemption. Yes indeed, “The Lord is my Shepherd I shall not be in want. He makes me lie down in green pastures; he leads me beside quiet waters.”