“When a high school student is the one that leads the family, lives are changed,” the speaker said, to applause from listeners. Michael Gormley, a keynoter at Steubenville East, was speaking Saturday to an estimated 2,400 youth and adults gathered at UMass Lowell for the July 12-14 youth conference. About 200 of them came from at least 14 parishes in the Worcester Diocese, according to Timothy T. Messenger Jr., director of the diocese’s youth ministry, New Evangelization Worcester for Youth and Young Adults.