Next, consider Romans 12:1-2:
Therefore I urge you, brethren, by the mercies of God, to present your bodies a living and holy sacrifice, acceptable to God, which is your spiritual service of worship. And do not be conformed to this world, but be transformed by the renewing of your mind, so that you may approve what the will of God is, that which is good and acceptable and perfect.
In Proverbs 23:7, we noticed that who a man really is – his essential character – is revealed in how he thinks. In contrast with that, this verse says we can be “transformed by the renewing of [our] mind[s].” Does this mean that I can transform my heart and character by controlling my conscious thoughts closely?
There are four hints that this is not quite what Paul means, although it’s close. First, the prerequisite for verse 2 is verse 1, our surrender of ourselves to God. Paul assumes we have already settled the heart issue at a deep level. Second, Paul talks about the renewing of our minds, instead of the protection of our minds. That’s very interesting! Apparently the problem isn’t that things are getting in that shouldn’t, but that our thinking is following old patterns instead of the new ones God has for us. Third, Paul contrasts this with being “conformed” to the world. This suggests that the issue isn’t so much specific tempting thoughts or images as it is moral standards and value systems. Fourth, the explanatory phrase that follows says we need our mind renewed so that we will approve what the will of God is. Some translations use the word “prove” instead of “approve”. In either case, the meaning is that we will work out for ourselves in our own experience what the will of God is and that it is truly best for us.
One more hint as to Paul’s meaning comes from considering what “mind” and “thinking” refer to. On the one extreme, there is the world of our conscious thoughts. On the other, there is the conglomeration of everything that is in our minds, whether we are aware of it or not. This would include the presuppositions we hold, our value system, our buried fears and hopes, our unconscious prejudices, the perspectives from which we view the world, and much more. When we use words like “mind” or “thinking” our meanings can range from one extreme to the other or settle anywhere in between, depending on the context of what we are saying. An exploration of the word “mind” and related phrases in the New Testament suggest that the New Testament writers usually meant more than just our conscious thoughts when they used these terms.
Putting all this together, I would suggest that the best interpretation of the renewing of the mind mentioned in Romans 12:2 is this: a) first we settle the heart issue by surrendering our lives to God (verse 1), b) then we let God begin changing the ways we think – not just specific thoughts, but our moral standards and our assumptions about life and so on – so that we learn to value what he values, and c) as a result our character and lifestyle are gradually transformed into what is pleasing to Him.
So how does this affect the GIGO doctrine? It supports it in one sense. Under this interpretation, Romans 12:2 means that when we surrender any area to God, we should expect him to begin to challenge our old ways of thinking about that area. If we find ourselves thinking thoughts that we now recognize as false, we need to discipline ourselves to cast them away and believe the truth instead. However, there are some differences in emphasis from the typical GIGO approach. First, the point is not the specific thoughts, but rather the wrong standards and values that the world injects into our minds. Second, the question is not what enters our minds but how much of it we believe. Third, the danger is not primarily the thoughts that enter from the outside anyway, but rather the old, unrenewed patterns of thought still present in our own mental world. Fourth, the first and central catalyst for change in our lives is not our disciplined thoughts, but our yielded selves. Only after we have settled the heart issues can we find victory in mental battles.