The name Isaac—'laughter'—suggests his optimistic disposition, someone not afflicted by fear and doubt. Isaac serves as a type of Christ, honoring his father.
Based on his long friendship with God, Abraham could systematically calculate the reliability of God's promises even in the lack of visual evidence.
Abraham, the father of the faithful, did not have a blind faith; it was based upon observation of God's proven track record of faithfulness.
Just as the child of the flesh persecuted the child of promise, the spiritual children of God can expect persecution from those living according to the flesh.
John Ritenbaugh asserts that understanding comes through sacrifice and that our lives alternate between light (understanding) and darkness (confusion). Abraham's experiences teach us not to try to force God's will by contrivances of the flesh. When any sin or self- will is involved, the fruits of such an endeavor will be bitter …
If we hold fast to principles, though it may seem initially uncomfortable and fearful, we will eventually receive respect and even admiration.
Abraham is the only biblical character singled out as a type of God the Father. He is also the only one to be called 'friend of God,' and is a good model.