Who Is a Christian?
In the United States, there are over 1,500 denominations, organizations, and non-denominational groups that identify as Christian.
Suppose one is given a description of each of the over 1,500 groups who identify as Christian, and is then asked to sort them into those groups that are truly Christian and those that are not.
Some will consider all of the groups to be Christian, some will consider only one of the groups to be Christian, and others will consider some of the groups to be Christian and not others.
This begs the question, "Who is a Christian?"