In these passages Isaiah tells Israel that the troubles in their lives are due to their sins and transgressions against God. Israel was still doing religious rituals and going through religious motions such as fasting. However, God was not blessing them. They had departed from God in their hearts.
Isaiah told them, “Your iniquities I have made a separation between you and your God. And your sins have hidden His face from you, so that He doesn’t hear.” I believe that this is true today. Our sins separate us from God. When we are given over to the sins in our lives, God will not hear our prayers.
The Bible says that the wicked have no peace in their lives. However, the righteous do have peace. When we repent of our sins and walk rightly before God, we will be given the fruits of the Holy Spirit. Peace is one of those fruits. The others are ‘love, joy, patience, kindness, goodness, faithfulness, gentleness and self-control.’
Those who walk rightly experience a rich and full life here on Earth. More importantly, God will allow them into Heaven. In Heaven they will experience an eternity of joy. Knowing these things should provide ample motivation to turn away from sin and pursue living rightly before God.