The god Yahweh is, and all gods are, the antithesis of knowledge.
The classic case is that since mankind's arrival on earth until the 18th century and [wiki]Lady Mary Wortley Montagu[/wiki] and then [wiki]Edward Jenner[/wiki], news of smallpox vaccination had only reached the Islamic World (probably via their god) and so thousands suffered and died from it. Between the introduction of vaccination and the late 20th century, it was still a killer, but eventually, one of God's Blessings was totally defeated.
Now, it could have been that, at any point in history, God could have told us about this, but no... he decided to disfigure and kill people instead.
It was most strange that Yahweh, that god of the Israelites, waited until the 18th century, because that was the time when his churches first started emptying and science started to grow.
Bear in mind that God knows the cure for all cancers, but he is not going to tell us just yet.