We know Christians do not practice sin.
Practice shows behavior of some sort, so yes they do. But they don't sin because they are not in sin. They are freed from the law and death. A Christian still covets which is sin, but the coveting is not sin to a Christian (saint).
And you need to stop with taking different parts of the Bible, putting them in a blender and hitting puree.
1 John shows you are in sin and not resurrected. That is not written to us. James, same thing. He requires allegiance to a duty (keep the whole law).