The times GOD gave him the promise of descendants even without a son yet.
The time he believed GOD about HIS Promise, it was credited to him as righteousness and GOD assured him of the same by honouring his sacrifice.
But he went out of GOD's Promise to get a child with Hagar.

The time GOD gave him a new name, for he would be the father of many Nations.
The time GOD asked him to make sure that their bodies bear the mark of HIS Everlasting Covenant.
The time GOD gave Sarah a new name, for she would be the mother of many Nations.
But Abraham still offered Ishmael to GOD for a blessing because according to HIM, there is no way him and Sarah would have had their own son.

And GOD still reassured him of a son and of descendants after him.
But still, Sarah laughed at the thought of being a mother at such an age.

Thing is, GOD's Promises may look unattainable but the amazing thing is,...