Resolute evangelism

Acts 18:9 (Berean Study Bible)

Do not be afraid; keep on speaking, do not be silent.

Satan uses a loudspeaker and megaphone to blast the world with his lies and shrill. The cacophony created by the world and the devil is so loud that it drowns everything and everyone else out. God's children should not let the world and its megaphones drown the quiet and gentle voice of the Holy Spirit or His message of salvation.