We are called to be salt of the earth and light of the world in order that others may see our good works and give glory to our Father in heaven. Remember this was before light came on at the flick of a switch and salt could be picked up at the corner grocery. Salt and light meant life, our lives, lived gracefully, are meant to be signposts to eternal life. A current song has the lyrics "I want whatever she's got", live your life so that others will want what you've got and be ready to tell them what it is, the saving grace of Christ Jesus! It's a big responsibility but the Holy Spirit gives you what you need if you are willing.