Romans 12:1-2
1 I urge you therefore, 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. 2 And do not be conformed to this world, but be transformed by the renewing of your mind, that you may prove what the will of God is, that which is good and acceptable and perfect.

(all Scripture quotes from NASB)

What does it mean to 'prove what the will of God is?'

Prove (dokimazo [1381]): to try, discern, distinguish, approve, to determine whether a thing is worthy to be received or not, to bring forth the good in us; to test, examine, scrutinize, to see if a thing is genuine, to recognize as genuine, to approve, deem worthy;

Standing as living proof

Discerning His will

All of this is true, our words and our actions should certainly declare the reality of the reborn life. However, the verse at hand is looking at something different. Here, Paul is accenting the fact that without the complete change of our mind that comes from God, without that metamorphosis in our outlook and character, we cannot recognize the true nature of God's will, if we can recognize His will at all. The pagans of Paul's day, as well as the new agers of our own, largely recognize that there is a will, a higher power ruling over the events of this life. But, they neither recognize the true Source, nor do they recognize the true nature of that will. Prior to our own metamorphosis, neither did we recognize the beauty of our Lord. Rather, we found nothing in His appearance to recommend Himself to our love.

But after that metamorphosis! Oh, how wonderful, how marvelous are His plans as they unfold before us! Indeed, His ways are useful and beneficial to us, for He has freed us from our slavery to death and shown us the way to live. His ways are fully agreeable, for as we grow in Him, as we learn to trust Him ever more fully, we recognize that indeed all that He does is for our good, as we remain in His will. His ways lack nothing! They will always attain to their goal.

This is also the work of the Holy Spirit in us: that having offered ourselves, we are aided in hearing our daily instructions, we are aided in seeing the right course of action throughout each day, and having seen the course, we are aided in pursuing the course we see. By His aid, our spirit is cultivated, it grows to the fullness of the image of God. Barnes tells us that we must 'cultivate a spirit attached to God, and His kingdom and cause.' This, we cannot do except the Holy Spirit bring His aid to us. This, we cannot help but do, if we have truly devoted ourselves to Him.

It's only Reasonable!

The King James speaks of our life of living sacrifice as our reasonable worship. It's only reasonable. When we think on what He has done, it's the only sensible way to react. If we will only stop and think about who God is, what He has done, what He has promised, what other reaction makes any sense? It is only reasonable to commit to being a living sacrifice, holy and acceptable to Him.

"God deals with us as with rational creatures, and will have us so deal with Him," writes Matthew Henry. God never asked us to set aside our brains to follow Him. No, He asked that we start using them for real. He asked that we start thinking reasonably and rationally as we never had before. We tend to talk of our belief as blind faith, but that's not really true. It's faith with eyes wide open. It's faith based on very reasonable and well-reasoned understanding of the case God has presented.

When we have studied what He has revealed of Himself, when we have learned the truth about how far He has been willing to go to make His love for us understood, when we see how much He has been willing to go through to save us from ourselves, it is only reasonable, it is thoroughly understandable and right, that we would devote ourselves to Him. God has shown us the reality of our ways. We must be fools to continue in our sins when He has given us such understanding. We must leave our reason behind to pursue a course of death when life has been laid before us. This is the unreasonable choice.

To know His love and respond to it with all the love we have is the truly reasonable course. There can be no other reasonable reaction! He has revealed to us who we are, but He has come with an assurance for us: He is offering a sanctification that is just as thorough as our corruption has been. He doesn't stop at cleaning up our minds. Nor does He settle for only cleaning the outside. It's a thorough work that He seeks to do, and being as it's Him who seeks to do so, we are assured that it is a thorough work that will be done. We can fight Him or we can help Him, but if He wills it, it will be done. Thank You, Lord!

So, here we are with this reasonable reaction to God's efforts on our part. What does our reason tell us we must do? How shall we devote ourselves to Him, now that we realize this is our most sensible desire? We cannot devote ourselves to Him unless we know what He considers pleasing. Fortunately, we have His own Word to declare to us what He considers pleasing.

Eph 5:8-10
8 for you were formerly darkness, but now you are light in the Lord; walk as children of light 9 (for the fruit of the light consists in all goodness and righteousness and truth), 10 trying to learn what is pleasing to the Lord.
Eph 5:17 So then do not be foolish, but understand what the will of the Lord is.

Our task, as we see from Ephesians 5:10 and 5:17, is to learn from what He has declared, what it is that pleases Him. Our task is to know His will so that we will no longer be foolish! There's a revelation for us, if we still need it! We, in this age of technology, think we are terribly smart, yet God's verdict remains much the same. The wisdom of the world remains foolishness, for it leaves the real problems unsolved and unconsidered. The real problems are all one: we by and large continue to refuse to know God's will, and we continue to attempt to thwart what little we do understand of His will. The world continues trying to live as though God was not, but He IS!

For those of us who have devoted ourselves to Him, then, there is no proper choice of action we can make other than to test everything by His will. Every decision we make should be checked to ascertain that it accords with His will. This requires that we expend the effort it takes to understand His will as He has revealed it. We cannot hope to succeed in this if we will not study His word, and learn from it what He desires. Even with understanding, however, there remains the difficulty of training our own willful nature to stop and think. We are people of action, we are people that never stop for directions until we are left with no choice. God is calling us to be people of wisdom, to start by seeking out the directions.

• Does this mean we should refuse to decide on a course of action until and unless we 'hear from God' on the subject? No. That's no better than visiting your local fortune teller.
• Does this mean we must drop what we're doing, and search through the Bible every time any choice must be made?

The point is to follow the directions Scripture has given you already. God tells His people to contemplate Scripture wherever they are, to have the Word on their doorposts, on their wrists, anyplace where it can be at ready access, whatever it takes to be constantly reminded throughout the day of what He has already declared for us. Why does He say to do this? Simple. His purpose in this is to so fill us with His will that we are not paralyzed by every choice, that choosing His will would be second nature to us.

This is God's goal for every one of us. This is what it means to have His word written on our hearts. There will remain sufficient situations that will require that we actually stop and prayerfully consider what is the best course. There will remain sufficient situations that will require that we devote some extra time to studying Scripture to understand the path God desires. But this devotion to His will is to be our strength, not an obstacle to our way.