The prefix trans means "across" or "beyond." When we are called to be transformed, it means that we are to rise above the forms and the structures of this world. We are not to follow the world's lead but to cut across it and rise above it to a higher calling and style. This is a call to transcendent excellence, not a call to sloppy "out-of-it-ness." Christians who give themselves as living sacrifices and offer their worship in this way are people with a high standard of discipline. They are not satisfied with superficial forms of righteousness. The “saints” are called to a rigorous pursuit of the kingdom of God. They are called to depth in their spiritual understanding.
The key method Paul underscores as the means to the transformed life is by the “renewal of the mind.” This means nothing more and nothing less than education. Serious education. In-depth education. Disciplined education in the things of God. It will call for a mastery of the Word of God. We need to be people whose lives have changed because our minds have changed.
True transformation comes by gaining a new understanding of God, ourselves, and the world. What we are after ultimately is to be conformed to the image of Christ. We are to be like Jesus, thought not in the sense that we can ever gain deity. We are not god-men. But our humanity is to mirror and reflect the perfect humanity of Jesus. A tall order! To be conformed to Jesus, we must first begin to think as Jesus did. We need the “mind of Christ.” We need to value the things he values and despise the things He despises. We need to have the same priorities He has. We need to consider weighty the things that He considers weighty. That cannot happen without a mastery of His Word. The key to spiritual growth is in-depth Christian education that requires a serious level of sacrifice.
That is the call to excellence we have received. We are not to be like the rest of the world, content to live our lives with a superficial understanding of God. We are to grow dissatisfied with spiritual milk and hunger after spiritual meat. To be a saint means to be separated. But it means more than that. The saint also is to be involved in a vital process of sanctification. We are to be purified daily in the growing pursuit of holiness. If we are justified, we must also be sanctified."
R.C. Sproul, The Holiness of God, p. 163-164