“It is the duty of every Christian to be Christ to his neighbor.”
Because “Christian” means “little Christ,” we are to walk in His steps, embodying His character in truth and grace, alongside those who don’t yet know Him. We aren’t Jesus, but we get to be like Him as He changes us.
“… whoever says he abides in Him ought to walk in the same way in which He walked.”
—1 John 2:6
For my money, this is the most challenging command/invitation in Scripture.
Image credit: “Neighborhood #1” by the woodstove on Flickr