19 And not being weak in faith, he did not consider his own body, already dead (since he was about a hundred years old), and the deadness of Sarah’s womb.
Verses 19 to 21 amplify Abraham’s hope of verse 18.
19 And not being weak in faith,
Abraham’s and Sarah’s bodies were becoming increasingly weak, but his faith did not weaken. Doubt was not in his vocabulary. He did not waver in faith; he did not vacillate between doubt and faith. Weak or wavering faith is doubt. He trusted God for 25 years to fulfill His promise.
he did not consider [evaluate attentively] his own body, already dead (since he was about 100 years old, he was sexually dead),
If Abraham would have looked at the reality of his 100 years of age and sexually dead body, he would not have exercised faith. He did not factor in his sexual deadness when appropriating his faith.
and the deadness of Sarah’s womb.
Another obstacle to his believing the promise of God was Sarah’s sexual deadness. It was not possible to have children by normal sexual relations. Far from believing without support, Abraham believed in the face of the facts sharply disparate to human evidence. From a human viewpoint, his situation was without hope.
We need to trust God even when the situation looks impossible.
Faith is weak when it allows itself to depend on human dynamics. Faith does not reject reality, but it is not limited to the best estimates of what is possible. Only God can give life where there is no life. He is not bound by the creation order.
When we believe in the promise of John 3:16, God gives us eternal life. We know nothing about obtaining salvation apart from God’s Word. When we claim 1 Peter 5:7, God frees us from anxiety. This is holding God to His Word and believing His promises. His Word is His bond; He will never go back on it. That is why we can trust the naked Word of God and the promises it contains.
Faith does not ignore the facts but sees beyond them. It is no escapism from reality nor is it fideism (faith in faith). True faith always rests on the facts of God’s promises. Thus, faith both recognizes facts and sees beyond the facts. Abraham weighed the stark reality of his sexual impotence but he believed God nevertheless. He counted on God to be true to His Word. There is no merit in faith itself but in what faith believes. There is no virtue in self-delusion.
On the other hand, rationalism (belief that reason alone is the way to truth) is not enough to reach truth. Reason cannot autonomously judge revelation. It is too finite, too fickle, because philosophy cannot come to universal truth. Recent secular thinking acknowledges the failure of philosophy. Its attempt to sit in judgment on the Word of God has failed. This presumes that the self (solipsism) is ultimate and always ends in a fragmented view of truth. This presumption sets up bias against another alternative. The bottom line is that this is a spiritual issue, not a factual issue. There is another reality beyond self—faith in the Word of God. This faith gives a universal view of reality deduced by God for man.
There is a difference between credulity and credibility. Faith is not gullible or naïve. True faith involves critical analysis; it is not uncritical of any idea that comes down the pike. Neither is it susceptible to any thesis that comes out of the blue. It is not trust without objectivity. The mumbo-jumbo of blind trust is not biblical faith. Acceptance of any propaganda and the attempt to justify it at the expense of reason is credulity. Abraham indeed saw the reality of his sexual capacity. Doubt would have looked at his body as dead sexually without any other alternative.
Strong faith, not a weak faith, rests on the facts and promises of the Bible. Abraham believed God in spite of the circumstance that he was unable to impregnate his wife, for God had given him a promise. The situation appeared hopeless.
There was a 25-year period between God giving the promise and the birth of Isaac. True biblical faith rests in the idea that God spoke to man in words. Abraham “considered” the reality of his situation but did not doubt. True faith has substance (He 11:1). There is both a humility and confidence in believing what God says.