Marc is really worth quoting here:
In this week’s edition of Joel News International I focused on the question: how many people in Europe follow Jesus? Three different studies, using different definitions of ‘committed Christian’ and varying methodologies, came up with multiple indications: 1.1% (GEM), 3.5% (OW) and 4.2% (emRG). My colleague Andreas Wolf from Germany says he has most confidence in the higher percentage, and suggests that in God’s Book of Life it might well be 10%. Wolfgang Simson disagrees with him and stresses that the issue is not about what people profess, but whether they really live surrendered lives and take their orders from Christ the King. He estimates the number of ‘real Jesus followers’ at just 0.1%. What is certainly clear though is that Europe is probably one of the most needy places in the world today.