Windows help people escape from fires. But that isn’t their primary purpose. The primary purpose of a window is to let in light. (Windows also let the curious mind see what squirrels are doing in the backyard.) 🙂
The Christian at their workplace is to be a window for the unbeliever to see into a different world. Philippines 3 says, “Our citizenship is in heaven.” What this means is that you, in your professional capacity, are a window for people to look into heaven. The light of another world streams through the windows of you. The light source? Jesus enthroned in your heart.
Here in Nebraska I can step from prairie USA into Afghanistan by knocking on a door or two in a certain neighborhood. The living rooms of these refugees are a clear window into Afghani culture. Similarly you as a citizen of heaven are a cultural ambassador modeling heaven for those you are interacting with. They hear your heart, they look into your eyes and see angelic aspirations, they ponder your peace in trial, and begin to envy the living hope you know.