Some may be familiar with the term "nominal Christian". It is often used to designate church members who are not true Christians or others who declare themselves Christian but don't attend church at all. In the normal context, labeling someone as a nominal Christian is a putdown. That term indicates someone who is deceitful or sadly deluded, neither of which is very complimentary. For those who think the churches are full of such people, it is a sad indictment of Christian Orthodoxy's effect even on those who claim an affiliation.
For me, the idea of nominal Christianity is not quite so negative. I think that in a very real sense most all of us who claim Jesus are at best nominal Christians. Of course, by Christian I mean one who tries to be a follower of what Jesus taught, not someone who has practiced some sort of church prescribed salvation ritual. Such make one no more a Christ follower than merely entering the church building does.
In effect, we can probably anticipate being nominal Christians, ones who are not fully aligned with Jesus, all of our lives. Try as we might, much of what Jesus taught is beyond our ability at present. The divine love which Jesus demonstrated is vastly different from the definition of love which we have inherited, the kind that involves a sort of contractual bargain. The unconditional acceptance and unrelenting concern for another's well being which Jesus exemplified is immensely foreign to our minds.
The church's attempt to divide humanity into neat little subgroups- the saved and the lost, the nominal Christians and the real ones- is a loser's game. We are united in the brotherhood of sinfulness (Romans 3:23). Jesus provided no basis to claim exalted status over anyone else.