The radio dial and the TV remote control enable a person to change Focus from one signal or channel to another.

When the channel is changed a different signal is received and played.

You receive a different message with a different effect on you.

When Jesus said "Man shall not live by bread alone, but by every word that proceeds out of the mouth of God." (Mat 4:4,) He was speaking to the importance of being turned into the message of God rather than the message of Satan.

Your Mind is a Tuner. It focuses by an act of your will on a source and its message.

If your Mind is not tuned to the Word of God you are undoubtedly tuned to Satan.

There aren't really but two channels/stations available.