A light bulb is an electric light. It’s a glass bulb containing a wire filament. Electric current is passed through the filament when it is heated. When the filament is heated the bulb glows with light.
When you don’t know God you are a lightbulb that is switched off. You have not yet stepped into you’re intended purpose which is to shine for God’s glory. When you accept Jesus as Lord, an electric current is passed through you. You are now filled with the Holy Spirit, light bulbs start to switch on all around you. Because of this heat and electric current within you, the Holy Spirit, your light bulb can now shine.
Don’t remain a light bulb that is switched off. Instead, be all who God created you to be and let your light shine.
You are the light of this world
Mathew 5:14
Let your light shine before others, that they may see your good deeds and glorify your Father in heaven.
Mathew 5:16