In two of the largest Muslim countries in the Middle East it appears that the population is evenly split between those who are devout Muslims and those who are secular and atheistic. In both of these countries, the majority of the members in the convert church have come to Christ out of secular Muslim identities. At the same time, in other countries, most of those coming to Christ had been devout, practicing Muslims.
The path to faith in Christ often progresses from devout belief, to agnosticism, to atheism, and then, after a prolonged period of searching for answers to questions that Islam cannot answer, to faith in Christ. God is drawing many to himself from among the millions of nominal Muslims around the world. In general, though, it would seem that nominal Muslims are no more or less receptive to the call of the Gospel than are devout Muslims.