We recognize that not everyone thinks the same. That is perhaps the reason why church theology places no emphasis on thinking about its implications. Too much individual thinking will inevitably lead to different understandings, and that cannot be allowed if doctrinal correctness is essential.
Encouraging careful thought will raise questions about which verses in the scriptures are really paramount, and which ones are of little importance. When the verses supporting grace versus obedience are juxtaposed, one or the other has to be emphasized, and that is an arbitrary decision. Of course, if one wants to give the Old Testament equal weight in the plan of God, a case might be made for the preponderance of the Bible selling obedience. But, then, why did Jesus come proclaiming a new way. Obedience as the route to righteousness had been the norm for thousands of years in every religious system ever devised.
So what is a thinking man’s theology? It is whatever you decide to believe based on a personal evaluation of the options. It is not what has been handed down from our forefathers and blindly accepted as true because of mere tradition.
Yes, this theology will vary between individuals. Its common elements will those that make sense to everyone after careful reflection. It will not be the regurgitation of historical thinking about God and our relationship to Him, because that has been dominated by those who claim that they alone should think and the rest of us should mutely follow.