What does the Bible say about our thoughts?

The Bible teaches that thoughts are crucial as they are the immediate births of the soul, reflecting its true condition. Passages like Isaiah 55:7 and Psalm 119:113 illustrate the necessity of forsaking vain thoughts and loving God's law. When a person's thoughts trouble them, it signifies a serious conscience that desires to align with God's principles. Therefore, it is essential for believers to regularly examine and guard their thoughts, understanding that allowing vain thoughts can lead to sinful actions.