Saturday's My Utmost for His Highest talks about how to act when God speaks. The text is Peter walking on Water: Matthew 14:22-33. Here is what Oswold Chambers had to say about that:
The wind was actually boisterous, the waves were actually high, but Peter did not see them at first. He did not reckon with them, he simply recognized his Lord and stepped out in recognition of Him, and walked on the water. Then he began to reckon with the actual things, and down he went instantly. Why could not our Lord have enabled him to walk at the bottom of the waves as well as on the top of them? Neither could be done saving by recognition of the Lord Jesus.
We step right out on God over some things, then self-consideration enters in and down we go. If you are recognizing your Lord, you have no business with where He engineers your circumstances. The actual things are, but immediately you look at them you are overwhelmed, you cannot recognize Jesus, and the rebuke comes: "Wherefore didst thou doubt?" Let actual circumstances be what they may, keep recognizing Jesus, maintain complete reliance on Him.
if you debate for a second when God has spoken, it is all up. Never begin to say – "Well, I wonder if He did speak?" Be reckless immediately, fling it all out on Him. You do not know when His voice will come, but whenever the realization of God comes in the faintest way imaginable, recklessly abandon. It is only by abandon that you recognize Him. You will only realize His voice more clearly by recklessness.
How many times to we sit and wonder if God is speaking? How many times do we sit and ask God over and over to speak to us when he already has spoken. We are quick to judge Gideon for "throwing out the fleece" (Judges 6:36-40) when we do essentially the same thing.