John 14:5

5.Thomas saith to him. Though, at first sight, the reply of Thomas appears to contradict what Christ had said, yet he did not intend to give the lie to his Master. But it may be asked, In what sense does he deny what Christ asserted? I reply, the knowledge possessed by the saints is sometimes confused, because they do not understand the manner or the reason of those things which are certain, and which have been explained to them. For example, the Prophets foretold the calling of the Gentiles with a true perception of faith, and yet Paul declares that it was a mystery hidden from them, (Ephesians 3:2.) In like manner, when the Apostles believed that Christ was departing to the Father, and yet did not know in what way he would obtain the kingdom, Thomas justly replies, that they donot know whither he is going. Hence he concludes that they know still less about the way; for before we enter into a road, we must know where we intend to go.