The Promise Came through A Son [Genesis 17]

 ³Abram fell on his face, and God talked with him, saying,
    ⁴"As for Me, behold, My covenant is with you,
         And you will be the father of a multitude of nations.
    ⁵"No longer shall your name be called Abram,
         But your name shall be Abraham;
         For I have made you the father of a multitude of nations.

 ⁶"I will make you exceedingly fruitful, and I will make nations of you, and kings will come forth from you.

 ⁷"I will establish My covenant between Me and you and your descendants after you throughout their generations for an everlasting covenant, to be God to you and to your descendants after you.

 ⁸"I will give to you and to your descendants after you, the land of your sojournings, all the land of Canaan, for an everlasting possession; and I will be their God."

Thirteen years later God speaks to Abram again and this time He changes Abram's name to include His.  He will now be called Abraham and his wife became Sarah.   Then God gave him a part in the covenant - he is to circumcise all the males.  There was a moment of disbelief on Abraham's part. He thought that God has waited too long to keep the promise - he was 99 years old and Sarah was only ten years behind him. "Then Abraham fell on his face and laughed, and said in his heart, 'Will a child be born to a man one hundred years old? And will Sarah, who is ninety years old, bear a child?'"  (v.17). 

His son Ishmael was thirteen.  Abraham was sure he wasn't understanding God correctly, so he offers Ishmael before Him.  But God said, no, that was not the way He was going to fulfill His promise to Abraham.  God told him he and Sarah were going to have a son named Isaac in the next year.  Then his moment of disbelief changed and he got up and circumcised every male that day.  God had spoken and Abraham believed Him and in faith did what God had asked.  The waiting and wondering was over.

God Almighty, You are a promise keeper.  You promised to make a nation where You would be the people's God.  Thank You that You fulfilled that promise through a son.  You fulfilled it completely through Your Son Jesus.  He made it possible for all people to have You be their personal God and to walk blameless before You.