Heb 6:15 And so, after he had patiently endured, he obtained the promise.
Many of us have no problem trusting God but struggle with waiting patiently. It is one thing to claim the blessings of Abraham, but can we withstand the wait? God promised Abraham to bless him with a son. 10 years go by, still no son. His wife suggested they have a son by his maid Haggar. God comes back to clarify that the son of the promise would not be by a slave girl but by his barren wife now 10 years older from the first message. It takes another 15 years before Issac is born (25 years of total wait). Rom 4:18-19, 18 In hope he believed against hope, that he should become the father of many nations, as he had been told, …19 He did not weaken in faith when he considered his own body, which was as good as dead (Heb 11:12) (since he was about a hundred years old), or when he considered the barrenness of Sarah’s womb.”
The strength of nature, as well as grace, is from God He can make the barren soul fruitful, as well as the barren womb, but notice this, of all promises of God, in the Bible for children never came immediately even of Jesus coming into the world. From prophesies you hear something likes, “next year around this time you shall bear a child”, is that not roughly the life cycle of pregnancies? And that requires patience. No woman who gets pregnant today expects the child today. They hold on to the first fruits by faith. Jas 1:4 “But let patience have its perfect work, that you may be perfect and complete, lacking nothing”. Why? 2Co 1:20 “For all the promises of God in Him are Yes, and in Him Amen, to the glory of God…”