WRONG! This was NOT a "Christian concept" but the work of the Roman Catholic Church.
Do not confuse the two.
Evangelical Christians like Jerry Fallwell and Pat Robertson would have been burned at the stake right alongside the Jews and other "heretics". That was the fuel that ignighted "Protestantism".
As for it being a "Catholic concept," that's only partly true. While Protestants were burning in Spain and France, Catholics were drawn and quartered in England, Ireland, and othewise being killed in the Holy Roman Empire and Scandanavia.
It's true that the burning of heretics was not a Protestant practice.
Protestants killed Catholic "heretics" by hanging, drawing and quartering, or by simple beheading (if they were nobility).
However, the people involved were just as dead, weren't they, berned?