If someone abandons the Muslim faith what is their punishment under the Sharia Law (which is based on the Koran)?
Not just Islam but in all Abrahamic regligions i.e. Christianity, Judaism and Islam, the original penalty of apostacy is death (Deuteronomy 13:6-9) However it is not necessarily applied in every, Christian, Jewish or Muslim country. Some countries do implement this but most of the countries dont take this seriously like Pakistan, India where there is democracy and United Nation humanity laws are applied.