When we cannot let the past go, we are not free. When we worry about the future, we are not free. In the meantime, we are easily enslaved by thinking all kinds of thoughts that do not draw us any closer to God. These are generally self-centered thoughts that can waste a lot of our precious time. So give your heart and mind to God that he might give you good and right thoughts always. To master your thoughts, let the Lord master you first.