Gen 17:17 Then Abraham fell on his face and laughed, and said in his heart, "Shall a child be born to a man who is one hundred years old? And shall Sarah, who is ninety years old, bear a child?"
Gen 17:18 And Abraham said to God, "Oh, that Ishmael might live before You!"
Can some body laugh at God and still be called a prophet of God? Abraham laughed at God. When God was saying to Abraham that Sara is going to bear a child, he could not believe it. Reason was simple circumstances were not conducive for Sara to bear a child. Abraham was 100 years old and Sara was 90 years old.
People of such age can never have children. That statement is true until God comes into equation. Till the time a person looks at situations that how big they are, it is very difficult for that person to believe that God is bigger than those problems. That's what exactly happened to Abraham. He was looking at his circumstances and could not believe that God can do something about the situation that is impossible.
Abraham who had walked with God, who had talked with God, should have known by this time who his God is. But it looks he could not grasp who his God is and what God can do for him.
Not only Abraham could not believe instead he gives a suggestion to God saying "Oh, that Ishmael might live before You!"
God's reply to Abraham was kind of thanks but no thanks for your suggestion Abraham, I am God and I know what I am talking about. Here is what God said.
Gen 17:19 Then God said: "No, Sarah your wife shall bear you a son, and you shall call his name Isaac; I will establish My covenant with him for an everlasting covenant, and with his descendants after him.
Gen 17:20 "And as for Ishmael, I have heard you. Behold, I have blessed him, and will make him fruitful, and will multiply him exceedingly. He shall beget twelve princes, and I will make him a great nation.
Gen 17:21 "But My covenant I will establish with Isaac, whom Sarah shall bear to you at this set time next year."
In other words God is saying to Abraham, "You don't get it Abraham. Sara is the one who is going to bear the child and I am not going to settle for a secondary choice."
How often we try to settle for secondary choices. How often we fail to get the God's best. Abraham had almost prepared to miss God's best choice. He had absolutely no idea what God had stored for him and God had explain to him.
Well may be Abraham would not have understood the full extent of what God was giving him. Even till his death probably he may not have had even the slightest of idea that how great God's plan for him was. Today when we look back we know exactly what God was trying to do there.
God said to Abraham that God is going to establish His covenant with the child that is going to be born to Sara and this covenant is going to be an everlasting covenant. Ishmael was not a son of promise but Isaac was. God's promises can come to pass only the way He has promised them. God will not change his plan just because Abraham wants it to be changed. God is not going to replace Isaac with Ishmael as they both represent totally different things.
Well God was preparing to send the savior of the Word the Lord Jesus Christ into this World and He was getting ready to redeem the mankind that had fallen in sin. Jesus came into this world through the lineage of Isaac. God was preparing to save people from their sins and that had to happen through Sara. God was Himself coming down into this World through the decendants of Abraham and Sara.
It was such an important task because without it there was no redemption from sins. Without it every single person on the planet earth was going toward hell and there was no rescue for them.
God's promise to Abraham came to pass. Sara gave birth to Isaac. Jesus was born in the lineage of Abraham after 42 generations. Does that tell you that God of Abraham, Isaac and Jacob is a God who keeps His promises even after 42 generations. He is a promise keeping God.
Through the death of Lord Jesus on the cross, He has established an everlasting covenant. And to become a partaker in the everlasting covenant all you have to do is turn to Jesus and accept Him as your personal savior.
John 1:12 But as many as received Him, to them He gave the right to become children of God, to those who believe in His name:
Are you ready to receive Jesus as your personal savior? then pray this prayer from the bottom of your heart.
Lord Jesus I know that I am a sinner. Lord I believe that you came into this world to save sinners from their sins. Your blood that was shed on the cross cleanses all sins. Please fogrive me of my sins and give me a new life. Please come into my heart and be the king of my life. I surrender my life into your hand. I pray in Jesus name Amen.
http://www.csicouncil.com/article.php?story=20090104115232934