The Reformed Christians today (especially in the West, particularly in America) are known to be lack of evangelistic, if not anti-evangelism. It's a sad thing. Some blame this all to way to John Calvin. The defense would be that Calvin had to deal with Rome and worked hard correctly what Rome has perverted in Biblical and Systematic Theology. But there were hints of John Calvin being very zealous for evangelism.
One of such I came across recently from a Facebook post:
"If we have any humanity in us, seeing men going to perdition, ... ought we not be moved by pity, to rescue the poor souls from hell, and teach them the way of salvation?" [1, 2] (From a sermon on Deuteronomy 33)