Would it be a good thing if no Christian was allowed any position in government?

[Anomalocaris]

It depends on how you do it. The shot gun approach of barring christians from government in a country where christian influence is culturally strong and the population is susceptible won't accomplish anything lasting. It would give substance to the perpetual christian slimy whine of persecution, and would but white wash the problem of christian influence. A more effective, albeit a more tedious and time consuming approach would be to raise the education level of the entire population until those who would remain christian in any substantive way would naturally be seen as unfit for responsibility, much less government, without there needing any legal bar to them.