1 SAMUEL 17.4-5: And there came out from the camp of the Philistines a champion named Goliath of Gath, whose height was six cubits and a span. (5) He had a helmet of bronze on his head, and he was armed with a coat of mail, and the weight of the coat was five thousand shekels of bronze. (ESV)
This battle of David facing Goliath was such a mismatch of size and weaponry that references to it have made their way into popular discourse. Huge differences of height, weight, power, or money are often likened to a “David and Goliath” confrontation.
A cubit was 18 inches in length and a span was 9 inches long. So Goliath was 117 inches tall, which was nine feet and nine inches. It seems to me that Goliath probably weighed somewhere between 400 and 450 pounds. And when you add all of his armor, he was a titanic soldier and instrument of destruction who was seemingly unstoppable and impenetrable.
As a comparison, a male grizzly bear is also about nine to ten feet tall standing on its hind legs, and it typically weighs 700 to 800 pounds. The armor and weaponry Goliath used would make him probably as dangerous and lethal as facing a grizzly bear.
So from my perspective, this disparity between David and Goliath was so enormous, David’s courage to fight Goliath was beyond bravery in battle. His courage, in my opinion, had to have been built upon his faith in God to help him win the victory. In verse 37 of chapter 17 David expresses that it will be the LORD who delivers him from Goliath.