Every Christian has a web (an oikos) of familial and social relationships. And by following its twists and turns, every Christian will encounter those who do not know the Gospel—but who need to.
Who is in your Oikos? A Greek oikos, or household, was not only a nuclear family but also relatives, close friends, and nearby servants' families. Our oikos includes those with whom we share kinship (blood or marital ties), interests (work, recreation, community), and proximity (neighbors, coworkers). Every Christian shares some space with people who have not heard the Gospel or seen it lived out in an authentic way.
Think of these three groups of people as being like major arteries off of which branch veins and capillaries that connect with people in your oikos. If you take a blank piece of paper and actually draw out these three networks, I believe you will be shocked to see how many people you interface with on a regular basis—and how many of them don’t yet know Christ as Savior and Lord.
Without fear of overstatement or presumption, I can tell you that these are the souls God wants you to reach for Him. If you don't reach them, who will? Who else has what they need—the Gospel—and has the relationships established that will grant them access?