Jesus answered, “I did tell you, but you do not believe. The miracles I do in my Father’s name speak for me,
“believed” (KJV) is actually in the present tense and should be rendered “believe” as it is in the NIV. Jesus has already told them that he is the Son of God, the Son of Man, that He had life in Himself, He has authority to judge, that He is the One Moses wrote about, He is the living bread that comes down from heaven, the One Abraham looked for, and many other attributes that could only be held by the Messiah. In addition to His testimony about Himself, Jesus has performed many miraculous signs that should prove to them that He is indeed the Christ, as scripture foretold (Isaiah 35:5-6). He has told them who He is and proven so by the miracles He is doing but they still do not believe. Their problem is not that they don’t know, but that they have no faith. Calvin notes that “they accuse His teaching of obscurity, when it was abundantly plain and distinct but for falling on deaf ears.”
Isaiah 35:5-56 Then will the eyes of the blind be opened and the ears of the deaf unstopped. Then will the lame leap like a deer, and the mute tongue shout for joy. Water will gush forth in the wilderness and streams in the desert.
The Jewish questioners are in possession of false ideas of what the Messiah would be and, as Morris points out, for Jesus to have given a “Yes” or “No” answer would have been misleading because He is not exactly what their concept of Messiah should be. He does answer their question, but in a way that reveals the true nature of the Messiah. He actually gives them a lot more than they bargained for.
W. Luthi makes the following observation: “Nowadays we can understand only too well these people, in their militant mood, rejecting a Shepherd who lets Himself be crucified. A God who fights His battles like a shepherd, and with sheep, is no more popular today than at the feast of the dedication of the Temple. That is where the hidden danger lies for us: it is so easy to whip up a crusading mood over the wrongs of the world and, in so doing, to deny the Shepherd and no longer hear His voice.” (qt’d in Morris 516)
We should be very careful to not tell God how to teach us or what to tell us. Instead of thinking that we know everything and that we know exactly what God wants to do and how, we should be more grateful for the revelations He does give and let Him be lord, and not us.