See Rom.4:19-20 "He did not weaken in faith when he considered his own body, which was as good as dead (since he was about a hundred years old), or when he considered the barrenness of Sarah’s womb. No distrust made him waver concerning the promise of God"

Heb.11:12 "Therefore from one man, and him as good as dead, were born descendants as many as the stars of heaven and as many as the innumerable grains of sand by the seashore."

3. When the promise was fulfilled it was so in a very precise way – as and when God had said!

Abraham responds to the fulfilment of God's promise concerning the birth of a son by Sarah.

He does so by acting in obedience to two commands that the LORD had also given:

a) To a recent and specific command – the naming of the child

b) To an older more general command – circumcision

If God is such a God who keeps His promises however unlikely their accomplishment might be it is incumbent upon His people to take His words of command seriously and not to live independently of Him. Our God is a God who takes note of details and we should be careful to be particular in our obedience.

A word of caution: "promise boxes" and the like. We need to understand how to read God's promises. Which promises are for us and which are not? There is something for us to learn in all of God's promises – sometimes the promises are general and refer to all but sometimes they are not. The promises given to Abraham and Sarah concerning the birth of Isaac are specific as to their detail and so not somehow to be "claimed" by an ageing childless couple.

I suppose that we would readily understand that to be true of this particular example but we need to read promises with care, to understand their contexts and their specificities.

Now I want to stand back and ask "Why was Moses eager to record these details in the way he did? What purpose did he have in mind?

Well, he was writing for the Israelites on the verge of entering the land of Promise.

Ø For them the promise of entering their land was long-standing and the wait had seemed interminable as they languished in Egyptian bondage. Moses wants the people to understand that delay is no problem to accomplishment with the Almighty!

Ø But the people had recently messed up big time. When they first got close to the borders of the Promised Land the spies brought back a negative report and the people rebelled – 40 years of wandering in the wilderness was the result as man after man died until only Moses, Joshua and Caleb were left of the generation that had left Egypt. But then Abraham and Sarah had messed up too trying by their own endeavour to have the child of promise! Their errors hadn't stopped God keeping His word and so the Israelites needn't fear either!!

Ø The Land of Promise was already occupied by hostile forces. Was it likely that such a people as the Israelites would be able to go in and conquer the land? Indeed when they did try to take matters into their own hands at Ai they were to be roundly defeated. But God had done the impossible for Abraham and Sarah – Moses wanted the people to learn that with God nothing was impossible!

We need to take these things on board too because we are confronted with similar temptations to give up hope:

Ø We can be frustrated by delay and become disheartened and discouraged.

Ø We can evaluate our circumstances with the eyes of sight only and forget the realities of the life of faith. Looking at the visible factors that we think we understand we can draw utterly wrong conclusions and end up living as though our circumstances are just too tough for God to do anything about them.

Ø We can focus upon our past failures and lose heart believing falsely that everything is forever compromised.

The lessons that Moses wanted the Israelites to learn from this story in the life of Abraham and Sarah are lessons we need to hear and learn in our own day.

Finally, let's not leave this passage without seeing it as part of the larger story of God keeping His promises concerning the coming of the Messiah – the Seed of the woman who would crush the serpent's head.

That promise had already been longstanding in Abraham and Sarah's day and was not yet accomplished. The birth of their son Isaac would form a part of the accomplishment as the Messiah would issue from Isaac's descendants. The fulfilment would come in the birth of our Lord and Saviour Jesus Christ and their a number of parallels between His birth and that of Isaac.

Briefly they are:

i) The birth of Jesus was due to divine intervention and not human planning

ii) Jesus' birth took place as the LORD had promised through the prophets

iii) He was born at the right time

iv) Before His birth his parents were told what to name Him and Joseph calls Him "Jesus" promptly

v) Joy – if Isaac's birth brought joy to those who heard about it how much more joy is to be bound up with the birth of the Saviour. You know the angelic declaration "Fear not, for behold, I bring you good news of a great joy that will be for all the people." You know how the shepherds reacted. You know about Anna and Simeon. You know about the wise men.

vi) Finally just as Isaac was circumcised the eighth day so was Jesus.

As we consider this passage let us take heart that God keeps His promises. Let us focus upon the One who is at the Centre of it all the Lord Jesus Christ. Let us remember that all the promises of God find their yes in Him.

2Cor.1:20 "For all the promises of God find their Yes in him. That is why it is through him that we utter our Amen to God for his glory."