They are out there, all around us. People who say they have no religion, but are Christians--- though they usually don't put it quite like that.
What they usually say is something like 'Christianity isn't a religion, it's a relationship with Jesus Christ!' But who ever said that the term 'religion' excluded the possibility of having a personal relationship with the Divine Being(s) of that religion? Ask a Wiccan or Neopagan if they have a personal relationship with one or more of their Gods or Goddesses. Chances are if they actually practice the worship-aspects of the religion rather than just the spell-casting aspects, they do.
Let's be rational. The majority of the Christians in the history of the Church considered Christianity a religion. The majority of Christians around the world today consider Christianity a religion. It's mostly just a segment of American Evangelicals that are going irreligious. So, let's accept it: Christianity is a religion, just like Hinduism, Wicca, Odinism and atheism. It's just that Christianity happens to be a religion established by God (as is Judaism) which is centered in a Church founded by Jesus Christ, the Son of God.
Why are there American Christians who want to deny their religion is a religion? It's the way we are raised. Most of us went to atheist public schools where one of the first things you learn is that religion is a bad thing you mustn't mention. I learned and internalized this message at such an early age I don't even remember the shock I must have felt to learn I wasn't supposed to say grace before eating lunch at school. And I started school in 1963 when the culture was still Christian enough that most teachers were still church-going Christians who probably expected that all the GOOD parents sent their children to Sunday school or catechism classes or, if Jewish, Hebrew school, and that this practice made those kids better citizens.
I believe that saying Christianity isn't a religion is actually supporting the religion-is-bad advocates who are responsible for the current upswing in child and teen atheism. Don't let's do it!
Some people may be saying the 'Christianity isn't a religion' thing for purely legal purposes. Because the Supreme Court has falsely ruled that the public schools may not promote 'religion', they figure if they get Christianity accepted as a non-religion they will be allowed to do Christian things in schools like have an elective Bible class or a voluntary morning prayer.
But this is like slapping the hands of the Hydra when you are supposed to be cutting off its head. The fact is Christian teaching is not only not unlawful in public schools, it is the reason that public schools were created in the first place!
The Founding Fathers were convinced that unless the people were believers in God, and in a state of rewards and punishments after death, they could not govern themselves but would fall into anarchy. The schools were to spread Christian moral theology among the people--- even the ones on the frontier where churches of the various denominations might not be readily available.
What the Founding Fathers never would have permitted is the situation we have today, where a non-theistic/anti-theistic religion that denies a state of rewards and punishments after death is not only considered equal to Christianity, but is considered superior, having been established as the official practice of the public school system and other government programs (though they have not yet declared atheism the official religion, perhaps because it is against atheist dogma to admit that they are a religion.
So that is why I call on all Christian believers within reach of my cyber-soapbox to take a stand against irreligious Christianity, and to fight for the right of Christians to be religious in public, just as atheists are allowed to be.