What was one advantage of the spanish inquisition for the monarchs of spain?

The Spanish Inquisition is one of the bloodiest and most deadly inquisitions in history. It is used for religious and political purposes. Spain as a nation state has emerged from the religious and political struggles of many belief systems, including Catholicism, Islam, Protestantism and Judaism. The rulers of Spain sought a way and tools to unite the nation, and intervened for the Inquisition in order to strengthen the Catholicism and eradicate other religions. The Spanish rulers mercilessly used the Inquisition to purify Spain, that even the Pope and the Church tried to intervene, but they were not successful. In one word, the Inquisition was a powerful weapon in the hands of the Spanish rulers to preserve power.