When I lived in Edinburgh, Scotland, I was often entranced by Edinburgh Castle. Built thousands of years ago when castles weren’t just for show but also for protection and battle, Edinburgh Castle sits high on hill, mostly surrounded by steep cliffs. At night, no matter where you are in the city proper, the lights of the castle can be seen.

The night before I moved back to the States, I was wandering aimlessly on the cobblestone streets of the city, listening to some melancholic music and thinking through WHAT IT ALL MEANS. (I don’t often have movie-worthy scenes in my everyday life, so when one presents itself like this, I milk it.) I stopped behind the pizza place off Princes Street and looked up to the castle, knowing this night view was my last.

It was the first time I really understood what Jesus meant when He talked about a city on a hill in Matthew.

“You are the light of the world. A town built on a hill cannot be hidden. Neither do people light a lamp and put it under a bowl. Instead they put it on its stand, and it gives light to everyone in the house. In the same way, let your light shine before others, that they may see your good deeds and glorify your Father in heaven.” — Matthew 5:14-16 (NIV)

I’ve pondered over this verse, and what it means for us as believers—to be like Edinburgh Castle, to be a city on a hill when darkness falls all around us. In my book Speak Love, I write about the power of words and how we can use our words to impact those around us. These verses illuminate four main ways we can use our words to positively affect others.

Four ways, Jesus says, that we are to shine:

• Be a light to the world.
• Be a city on a hill.
• Be a lamp on a stand.
• Be a light.

To be a light to the world, we have to speak love to the world. Think big first, He says. It’s like He is taking time to remind us that this story we are living isn’t just about us– don’t just think about the light, think about the world. And thanks to social media and the ability to print content on the WORLD wide web (case in point: this article), we are able to use our words to literally impact the entire world. Whether you want to translate the Bible for tribes who do not yet have it in their native tongue, move to the ends of the Earth to share the Gospel, or use Bible Gateway to understand a new translation of an old favorite verse to share in your writing, impacting the world with our words is easier than it has ever been before.

Don’t underestimate the massive impact your words can have. Ask anyone who has had a blog post or a tweet go viral, for better or for worse. What you assume will be read by a small population can reach a global audience in a disturbingly short amount of time.

Trust God with your words–with their potential and reach. Whether it is one conversation in a coffee shop in India with a young woman who has never heard of Jesus or one blog post that is read by millions, your words matter. You are the light of the world.

Annie Downs is an author who loves helping young people—especially teen girls and young women—overcome the challenges that life puts in the way of their spiritual development. She’s the author of Speak Love: Making Your Words Matter (Zondervan, 2013). Follow Annie at her blog, or on Facebook and Twitter.