I find this fascinating. Abraham was told to leave everything he knew, his religion, his family, and follow the Word of God into a foreign land. And Abraham did as the Lord commanded, he left everything he knew because he trusted God. Abraham was told by this same God to take his only son and sacrifice him. And Abraham did, certainly in his mind. Abraham did all these things that was commanded of him and many more because he trusted God. That is a very important part of Abraham's story that you completely ignored.
No, instead you scour the scriptures to find a sin, any sin, and when you find one, you make sure everyone you know sees, not his faith, or faithfulness, Not his commitment to God, respect and faithfulness to God. Not the judgment God has already given you about Abraham. God forbid, no, you make sure all your brethren SEE your judgment of him, you make sure they SEE his Nakedness.
The same thing was done to Noah, and todays religions do to David as well, all the time. And why? Always to justify disobedience to God. I might remind you that Abraham wasn't the Friend of God because of his sin, rather because of his Faithfulness.
And God never mentioned this sin you declare, never called it is sin, never addressed it even once in the entire Bible as a sin. But you do. You should think about that.
With all this "Faith" that Abraham exhibited, would God refuse him of some Grace? I would think not. But religions which did not the "work of Abraham" didn't receive God's Grace. They sinned too? Why didn't Grace abound in them? What made Abraham different?
It seems that God didn't give Abraham His Grace because he told a lie about his wife. It seems God gave Abraham His Grace because Abraham trusted in Him enough to do what He said.
So I don't think the Story about Abraham was intended to promote or excuse disobedience to God, I think it is clear that the Story of Abraham was to show what happens when we Love God and Trust Him enough to do as He says. This is what true "Faith" is. This is why he was forgiven and God never laid those sins against him. If God didn't remember, remind us through out the Bible, point out his sins, then surely us mere mortals shouldn't judge Abraham as a liar.
I think God was just keeping His Eternal Promise to Abraham that He told Cain.
Gen. 4:
7 If thou doest well,
shalt thou not be accepted? and if thou doest not well, sin lieth at the door. And unto thee
shall be his desire, and thou shalt rule over him.
Ex. 20:
6 And shewing mercy unto thousands of them that love me, and keep my commandments.
John 14:
23 Jesus answered and said unto him, If a man love me,
he will keep my words: and my Father will love him, and we will come unto him, and
make our abode with him.
24 He that loveth me not keepeth not my sayings: and the word which ye hear is not mine,
but the Father's which sent me.
Rev. 14:12 Here is the patience of the saints: here
are they that keep the commandments of God,
and the faith of Jesus.
Jesus Christ, the same yesterday, today and forever.
The story of Abraham wasn't about his sin, but about His obedience.