"But his delight is in the law of the Lord and in His Law he meditates day and night"
Transformation requires new thoughts. Transformation requires a new mental construct to live and to strive toward. It is impossible to be transformed if you do not meditate on biblical concepts and images of the future. If all you have are the thoughts that you are already thinking and the view of the future that you already have, then you will never be transformed. We are what we are thinking about. This is why the Scriptures are clear about the fact that we must take control of our thought life and inject the scriptural picture of the world, of ourselves, and of our future.
We too often allow the defeatest mentality of those around us to become the dominant thoughts of our life. This is a problem. God is sovereign and has allowed us room to make choices in our lives. If we make the right choices that move us down the path that He has designed us for, then we will thrive and be blessed. If we follow our own selfish inclinations and the temptations that present themselves to us, we will miss God's best for us. When we fill our mind with God's written word then it informs us; it sets boundaries for our actions; it impels us forward in righteousness; and it shows us how to maximize our gifts, abilities, and talents in righteous ways.