According to my informal and very unscientific survey, the three most familiar Bible passages of all time are Psalm 23, The Lord’s Prayer and John 3:16. Even non-church people recognize some part of these passages.
They are all really good, of course, but only John 3:16 shows up on signs at games and other televised events, which makes it slightly more famous. It is unknown if anybody, while watching a game, begins to frantically search for the Family Bible so that they can look up John 3:16 to understand what the guy holding his sign is trying to communicate. It is unknown, but my guess is that the number is pretty low, like maybe three people since TV started.
Psalm 23 is a poem or song that David wrote when God inspired him. He likely was in some distress and might have been running for his life.
David was a king and a warrior. He was also a shepherd and a poet/musician. He knew about sheep and about The Shepherd.
It seems to me that the message of hope and confidence found in The Twenty-Third Psalm is very much needed these days. You might not be running for your life, but you could feel confused and fearful.