Christ is not a book. Nor is Christ a religion. Christ is the reality of a human being choosing to embody the divine spirit of love, forgiveness, kindness and generosity within him (as best he can). So anyone can be a "Christian" regardless of their religiosity. Even an atheist.I left Christianity (partly) because I came to the conclusion that I couldn't practice the true Christianity of the Bible and remain a moral person. If you don't practice true biblical Christianity, how can you call yourself a Christian?
And no one will be able to do it perfectly.