BUENOS AIRES — The election of Pope Francis is raising spirits and hopes throughout the Catholic Church. But what has been the impact on the ground, and what are the prospects of a makeover for a church that often measures changes in terms of centuries rather than days and months? Many of the people who know Pope Francis best, leading Latin American journalists, scholars and religious leaders, say the genuine faith of the Argentinian pope is making a difference with people in the streets and in the pews. Convincing Catholics in high places, however, may be his greatest challenge.