Islam compared

Bob writes:

The comparison between Islam and the Soviet Union is a hit and a miss. Islam is no more unified than the components of the former Soviet Union. However, Islam has been around for over 1300 years and shows no sign of dying out. Communism will be an historical footnote in 50 years.

If we compare the contributions of cultures of the big 2 religions, Christianity has both modern science and modern democracy to its credit. Islam preserved Greek knowledge and according to the history I was taught, the renaissance was kicked off by the knowledge from Islamic culture coming to Europe and finishing off the dark age culture which was focused on the after life. I would like to find a good source which explains the differences between 11th century Islam which was active and competent at science and current Islam, which is not. Unless Islam regains its ability to support science it will never be culturally, economically, or militarily competitive.

If we look at mathematics, science, the arts, and hot sex, the Greeks were superior to Christian and Moslem cultures in per capita output.