In a teaching context to the law-focused Romans on the divine perspective of faith justification using Abraham to illustrate, Paul has this to say about the great Patriarch:
Yet he did not waver through unbelief regarding the promise of God but was strengthened in his faith and gave glory to God being fully persuaded that God had power to do what he had promised. (Romans 4:20-21)
Sorry, but the following does not sound like “not waver” or “being fully persuaded” to me:
His plot with Sara to lie and pass her off as his sister to the Pharaoh while in Egypt in an attempt to save his skin. (Genesis 12:10-20)
The plan concocted with Sara’s help to use their maidservant Hagar to conceive a child with Abraham as if God needed their help to work out his will. (Genesis 16)
A second lie in passing off Sara to Abimelech as his sister. (Genesis 20- Sara must have been some kind of ninety-year old looker!)
None of this sounds to me like Abraham was fully convinced that God had the power to deliver on his promise of a son. It appears to me that there were times when Abraham was fearful and doubting.
But he never quit. He never stopped going in God’s direction- even after his blunders. He was with God to the very end. This is why Paul could say of Abraham’s faith that “it was credited to him as righteousness” and how he could use him as a faith example for the ages.
As for those specific references about not wavering and being fully persuaded?
Well, this is the main point of this post.
It is called grace.
Through God’s grace-filled recollection of Abraham’s faith journey, those things vanish from the story. Grace accounted for them and removed them from the record.
I don’t know about you, but I am going to need the same type of grace-reckoning.
All prasies to the God of Abraham- and the God of grace!