What does "the take-up" mean?

Question

I couldn't find the proper meaning in the dictionaries. Could anyone explain to me what does the author mean by "the take-up" here in this excerpt?

There has been a trend towards setting the standard of Christian identity ever higher. David Martin notes that after the end of Christendom: ‘Christians have raised the bar about what it means to be Christian, and so inhibited the take-up.’ People have been placed into the secular category because they do not attain the ‘virtuoso performance’ of the elite. The apathetic middle ground, between committed Christian devotion and militant atheism, has been excluded from the Church.These people are thought of as secular.

Source: A Short History of Secularism

Answer 1

In this context, it means something along the lines of 'the rate of affiliation to the Christian religion by those who were not Christians up to this point'. Essentially, the reference is to the number of people who take up the opportunity to become members of the Church.