Failure is Not an Option
Why was David prepared to take on Goliath? Because he had a perception as to the real issues. David had the perception to realize that more was at stake than the mere defeat of Israel and the humbling of her pride. The honor and dignity of God was a stake.
In defeating the giant, David wanted the whole world to know that there is a God in Israel, that the battle is not won with human weapons, and that the battle is the Lord's and it is He who gives the victory.