* They were ambitious. Ferdinand and Isabella were both ambitious rulers who wanted to expand Spain's power and influence. They saw Columbus's voyage as an opportunity to explore new territories and claim them for Spain.
* They were devout Catholics. Ferdinand and Isabella were both devout Catholics who believed that it was their duty to spread Christianity to the New World. They believed that Columbus's voyage would help to bring Christianity to the indigenous people of the Americas.
* They were in need of money. Ferdinand and Isabella were in need of money to finance their wars against the Muslims in Granada and to pay off their debts. They saw Columbus's voyage as a way to make money by finding new sources of wealth.
In the end, Ferdinand and Isabella's gamble paid off. Columbus's voyage led to the discovery of the Americas, which brought great wealth and power to Spain.