Genesis 15:4-8; 19 NIV
 Then the word of the Lord came to him: “This man will not be your heir, but a son who is your own flesh and blood will be your heir .”  He took him outside and said, “Look up at the sky and count the stars---if indeed you can count them.” Then he said to him, “So shall your offspring be.”  Abram believed the Lord, and he credited it to him as righteousness.  He also said to him, “I am the Lord, who brought you out of Ur of the Chaldeans to give you this land to take possession of it.”  But Abram said, “Sovereign Lord, how can I know that I will gain possession of it?”
 "On that day the Lord made a covenant with Abram and said, “To your descendants I give this land, from the Wadi of Egypt to the great river, the Euphrates."
Yesterday we saw how Abram, although he was very grateful for all God had given him, still had this one great desire in his heart and that was for a son. God had promised him many years ago that he would have an offspring and here he is all this time later with nothing to show. As Warren Wiersbe puts it: "God had a glorious plan, and God made a gracious promise, but God seemed to be doing nothing!" Abram doesn’t need to hear platitudes or empty reassurances.
He expresses his disappointment to God, he pours out his heart. That's a good idea. And look at how God responds. He doesn't chastise Abraham or criticise him for being ungrateful. He simply reaffirms His promise to him. He has him look up and count at the stars of the sky. Even when life is dark, you can still see the stars. He tells Abram that his offspring will be greater in number than all the stars.
Remember here that Abram had formerly been a worshiper of the moon god. Now God asks him to look to the sky, the place of his old life, and consider the faithfulness of God.
Sometimes God takes us back physically or emotionally to places we would rather leave behind. He wants to redeem that place, to have us see that even when we unaware, or weren't looking for Him, He was always right there with us.
God doesn't expect Abram to figure out how to have an heir. Nor does He give Abram all the details of what He's going to do. All He asks is that Abram continues to trust, even in the face of real circumstances which would naturally make him give up all hope and faith in God's promises.
Maybe today you are really struggling to see how God can answer a heartfelt prayer or fulfil a longstanding promise. It seems impossible. Keep trusting His heart when you can't see His hand at work.
During the Boxer Rebellion, the China Inland Mission suffered greatly, and its founder, J. Hudson Taylor, said to a friend, “I cannot read; I cannot think; I cannot even pray; but I can trust.”