"I am not really writing to tell you of any new command, brothers of mine. It is just the old, original command. You may think that the original message is old, and yet as I give it to you again I know that it is always new and always true - in your life as it was in His." 1 John 2:7,8
Two things are really beautiful to me in these two verses: the fact that John doesn't even really need to name the "old, original command" for his readers to know what he means; and the fact that John has grown so old in the doing of that command that he calls "old and original" what Jesus, when He first spoke it, called "new."
Do you know which command he's talking about?
“Now I am giving you a new command – love one another. Just as I have loved you, so you must love one another. This is how all men will know that you are my disciples, because you have such love for one another.”
To be a "modern American Christian" would seem to require all sorts of things: attendances, reading, a particular worldview, a dash of patriotism, etc, etc.
To be a disciple of Jesus of Nazareth requires only one thing: LOVE.