Salt and light.

Romans 10:9

If you declare with your mouth, “Jesus is Lord,” and believe in your heart that God raised him from the dead, you will be saved.

Matthew 5:13-14

“You are the salt of the earth. But if the salt loses its saltiness, how can it be made salty again? It is no longer good for anything, except to be thrown out and trampled underfoot.

“You are the light of the world. A town built on a hill cannot be hidden.

Luke 8:16-17

“No one lights a lamp and hides it in a clay jar or puts it under a bed. Instead, they put it on a stand, so that those who come in can see the light. For there is nothing hidden that will not be disclosed, and nothing concealed that will not be known or brought out into the open.