What does that mean? Ah, brethren, it means to obey without reasoning. Way back in the garden of Eden, to which the Apostle refers here, when Eve was tempted, the serpent got her to reasoning instead of obeying. She looked at that tree, and it looked pleasant to the eye. That was perfectly true. It was good for food, and that was perfectly true. It was a tree to be desired to make one wise; that had its truth in it too. But what did the serpent hide from Eve? That the act would be disobedience, and the fruit would be death. In other words, Eve began to reason instead of obeying.
Remember that the Word of God is given to us for the obedience of faith. That is said twice in the epistle to the Romans—in the first chapter, and in the last chapter.