I once read somewhere that essence of all Christian teachings is"Love" and that of Islam is "Justice". And unlike "Love", "Justice"is not a matter of private relation - but that of social and legalenforcement. Hence, the Christian approval of secularism and Islamic dismissal of it. Some writers consider Christianity as "orthodox"religion (occupied with the dogma - instead of daily life matters)and Islam and Judaism as "orthoprax" religions i.e. their empahsis onoutward forms and rituals and laws. Clearly, the idea of separation ofstate and church is alien to Islam and Judaism - however, over theyears, Jews have developed a strong culture of intellectual skepticismthat has substantially watered down the "Orthodox" version of theirreligion. That's not the case with Muslims, unfortunately!In theory, both Christianity and Islam have libertarian as wellauthoritarian tendencies.
Re Christanity:

1. Render unto God what's God's and render unto Ceaser what'sCaesar's.(libertarianism)

2. Only the Holy Father has the right to interpret what is to renderedto God and Caesar (totalitarianism)

Re Islam,

1. God, not man, is the lawmaker. (totalitarianism)

2. There is no intermediary between man and God and every Muslim isfree to interpret the word of God. (libertarianism)

The devil lies in details (of practice). As remarked by Steve Sailer,if a Martian's entire knowledge of the world came from reading theBible, he would be bound to deduce, after hearing the thundering,angry voice of the Old Testament Jehovah, and reading of theconquests of Joshua, Gideon and David, followed by the gentle wordsof Christ and St. Paul, that those warlike, fighting Jews must havebeen kicking around the meek, cheek-turning Christians for the last2,000 years.

Or as someone said: "In theory, there is no difference between theoryand practice, but in practice, there is."