After watching Dr. Carson's speech at the prayer breakfast, it raised more questions in my mind than it answered. Dr. Carson brought up the biblical concept of tithing as a model of tax policy for a secular nation. I have to ask myself if this is sound.
While I do believe that the tithing system is a fair system as the good doctor points out, it's purpose was for the support of the religious system of the people of Israel and not for the support and financing of public works, a secular educational system, an interstate highway system, and on and on.
The second thought that comes to mind is that the notions of "the world" and "the church/kingdom of God" being two separate and distinct entities.
Two passages of scripture will point this out. Christ speaks of "the world" as being separate for His people, His kingdom, and His methods.
1)John 17:11-15
11 And now I am no more in the world, but these are in the world, and I come to thee. Holy Father, keep through thine own name those whom thou hast given me, that they may be one, as we are.
12 While I was with them in the world, I kept them in thy name: those that thou gavest me I have kept, and none of them is lost, but the son of perdition; that the scripture might be fulfilled.
13 And now come I to thee; and these things I speak in the world, that they might have my joy fulfilled in themselves.
14 I have given them thy word; and the world hath hated them, because they are not of the world, even as I am not of the world.
15 I pray not that thou shouldest take them out of the world, but that thou shouldest keep them from the evil.
2)John 18:35-37
35 Pilate answered, Am I a Jew? Thine own nation and the chief priests have delivered thee unto me: what hast thou done?
36 Jesus answered, My kingdom is not of this world: if my kingdom were of this world, then would my servants fight (use secular methods and tactics like politics, armed resistance, taxation) , that I should not be delivered to the Jews: but now is my kingdom not from hence.
37 Pilate therefore said unto him, Art thou a king then? Jesus answered, Thou sayest that I am a king. To this end was I born, and for this cause came I into the world, that I should bear witness unto the truth. Every one that is of the truth heareth my voice.
For christians to be true to the Master, they really need to understand that God and Christ are not trying to establish an Earthly government. They've already tried that and it didn't work. Collectively, men were not able to fulfill that ideal.
Dr. Carson is a brilliant neuro-surgeon. I have admired him for years. However, I have to admit that I wasn't that impressed with his thoughts on public policy. To be fair, and he admitted as much, he didn't have time to elaborate much.
However, what he has suggested seemed to conflate the spiritual with the secular. And, hasn't been even attempted by any other nation since old testament times. Not even by present day Israel. Seems a little naive.