What do Twelver Shia Muslims believe Imamate does?

Shia Muslims believe imamate allows for the power of divine law to be counited from Muhammed. Twelver Shias believe God’s law was completed though Muhammed but the guiding of people and explaining of the divine law is continued through imams, as in each generation there has always been a divinely appointed Imam to have authority over the matter of faith and law.