I n almost all foot racing, at some point in the race, each runner has to stay in his or her own lane. When you don't you can be penalized because stepping in someone else's path can cause injury or at least mess up their performance.
Lanes also make it possible to have everyone run the same distance on a curved track.
The Apostle John had a great concern that Jesus disciples stayed between the lines. He wrote to his readers as though he were their father. He didn't want to see them suffer in the same way I don't want to see my children suffer. If they stray outside certain lines in society, they will get hurt. If we don't stay in the lines that God has established for us through His Word, we will get hurt.