“City on a hill” is a term used by Jesus to refer to his followers when they are visible to others. Remember the song, “This Little Light Of Mine?” That idea comes from the same passage. The point, I think, is that when we live in such a way as to identify with Christ, it will be noticed.
I have been thinking about the faith community of which I am a part. There are people I know and love who have been on the journey with Jesus for many years, and others who are just starting out. (Some of these folks have been around a while, and only recently came to faith, which is exciting!) Each one of these folks is precious and valuable.
In difficult times, it can be hard to love people and stick together, and to live in integrity. If we make choices to follow Christ, day in and day out, we are like that City on a Hill, and we will not be hidden.