So faith comes from what is heard, and what is heard comes through the message about Christ.
You can’t control who believes, but you can control what you say.
If you don’t tell anyone about Jesus, no one will hear.
If no one knows, they won’t believe.
That’s easy enough math: 0 + 0 = 0
If you open your mouth and tell people what God has done and why He’s done it, some may just believe and be saved.