Genesis 20-22  Abraham moved away from Mamre and stayed in Gerar.  Once again he told Sarah to say she was his sister and not his wife.. and once again she was given to another man, this time Abimelech.  Once again, the Lord intervened and the truth came out. And, once again, the Lord takes Abraham out of the situation and blesses him through it. 

It is after this that Sarah becomes pregnant with Isaac and at 90 years old, she becomes a mom. "God has made laughter for me.. " she proclaims.  When Isaac was weaned Abraham held a feast. At the feast Ishmael mocked  Isaac and this made Sarah angry and she demanded that Hagar and Ishmael be sent away. So, they were. Once again, God intervened in Hagar and Ishmael's lives, rescuing them from certain death in the wilderness. 

After this, Abraham moved again, to Beersheba and made a pact with Abimelech. "And Abraham sojourned in the land of the Philistines for many days." 

Then, "God tested Abraham.."  This had to be the greatest test of all.. for God told Abraham to offer his son Isaac as a burnt offering.  Abraham did not hesitate, but prepared and took Isaac with him to the place he was told to go.  We know the story.. Abraham prepared an altar, started the fire, bound his son and raised his knife.. and only then did the Lord stop him and provide the ram.  "By Myself I have sworn, declares the Lord, because you have done this thing and have not withheld you son, your only son, indeed I will greatly bless you and I will greatly multiply your seed as the stars of the heavens and as the sand which is on the seashore; and your seed shall possess the gate of your enemies. And in your seed all the nations of the earth shall be blessed, because you have obeyed My voice." 

Father in heaven, we wonder at the way You worked in Abraham's and Sarah's lives.  We are amazed at Your command to Abraham to offer Isaac.. and that he obeyed without hesitation.  We wonder at our own lack of willingness to sacrifice things that mean a lot less than a son!  Help us Father, to hear Your voice and obey with all our heart.. laying down everything at Your feet.  You have a perfect plan and You are faithful in all Your ways.  I will trust You, Lord, in all things.. big or small.. as You help me to do so by Your gracious Spirit. May Your will be done on earth as it is in heaven. amen.