I don't agree. How can Muslims believe if they cannot hear the gospel?
Our pastor visits India rom time to time.and to get a visa he was not allowed to preach outside the church. However, unbeknown to him the church had rigged up large loudspeakers outside the church to broadcast his message. Preachers in that country face 6 months in jail for preaching outside the church but the go to jail and when the come out they preach outsie again and then do another 6 months.
The church is to spread the word, not to keep it to members.