Who asked for a sign? Who asked for a miracle? Those whose hearts were farthest from Him, the unbelieving, the hecklers, the critics. These people cared nothing for the real Jesus, so they occasionally became the objects of His scathing denunciations. He calls them "hypocrites" for asking for a sign.
Those who ask for signs or seek miracles, who put out the fleece like Gideon did (showing a glaring lack of faith), are actually casting insults on the Word of God. They are calling it into question. They are profaning His name, calling Him a liar because, if He says He will do something, and it is impossible for Him to lie, He will do it!
This can be very sobering. It brings to mind an advertisement that used to appear on television every once in awhile featuring a stern-looking woman dressed in a gown, who said, "It's not nice to fool Mother Nature!" and then thunder pealed! God, surely, takes our immaturity into account, but it is not nice to call Him into question. That is tempting Him. If He says He will do something, He will do it, according to His will. Therefore, calling for a miracle often characterizes carnality, not spirituality.
The next question, then, has to be, "Will not God work a miracle in answer to a prayer?" He makes a great many promises, such as healing, which is indeed a miracle. Will He perform a miracle for us? Yes, He will. But if we search His Word, we find more than a dozen qualifications for answered prayer, not just a couple. Some of them are of major importance, some of lesser importance, and He does not require that every qualification be met perfectly. Even so, divine healing in response to answered prayer is not automatic.
Whether or not God grants our request seems to boil down to three broad areas—four, actually, but three of them fall on us. One is the way we are living. A second is the understanding involved in the request. The third is the attitude in which the request is made. When those three are combined with God's will, the answer becomes clear: He will do it. However, He will do it in His time and in a way that will give credence to His Word, to His truth, to His purpose.