If something good takes time to come along, then the wait is worth it.
So if we had ordered something online and the delivery would take a few weeks, then it is either we wait out the time or we find other quicker alternatives.
For Abraham, he had been waiting for God to fulfill his promises and he had been waiting for 25 years already.
He had been waiting for the son that God had promised him and he had been waiting since he was 75 years-old, so time was not on his side as he reaches 100.
So even though God renewed His promises to him, Abraham was already thinking of other possible alternatives.
But Abraham would eventually see that God is indeed faithful to His promises and that He would do as literally as He said He would.
In the gospel, the leper who came before Jesus could also be suffering from the disease for a long time.
He had hoped for a cure, but time was wearing out his faith.
So with boldness, he said to Jesus, "If you want to, you can cure me." And Jesus said, "Of course I want to. Be cured."
And of course, God wants to fulfill His promises to us and to let us know that He loves us.
But as in anything that is really good, let us ask for the faith and patience to wait. In God's time, all will be well and good.