There are few other words to describe this: A Cairo court sentenced an atheist from a Christian family on Wednesday to three years in prison for insulting religion, firing up fears about the future of freedom of expression here just as Egyptians prepare to vote on an Islamist-backed draft constitution denounced by secular groups as failing to protect such rights. The convicted man, Albert Saber, is expected to be released on bail of about $167 pending an appeal. An open and avowed atheist, Mr. Saber, 27, was initially accused of circulating links to an offensive online video lampooning the Prophet Muhammad that set off protests across the Muslim world in September. Mr. Saber has denied promoting the video, and he is being charged for…