The Antichrist was written in 1888 one year before Nietzsche’s descend into madness and immediately after his Twilight of the Idols. Both books should be read under the aspect of the last words of his final original book, his autobiography Ecce Homo: “Dionysus against the Crucified.”
The German title can be translated as either “The Anti-Christ” or “The Anti-Christian”. It was likely meant to mean both. Dionysus has two opponents, one worthy of him, the other unworthy.
The name Nietzsche gives to his worthy opponent is Christ – hence Dionysus is the Anti-Christ. “In reality there has been only one Christian, and he died on the Cross.” – The Antichrist §39
As Nietzsche discusses Christ, the tone becomes ever warmer and even ecstatic. It becomes one of the most moving and powerful parts of the book.
The unworthy opponent is the Christian, who is undeservedly dignified by being treated to such elaborate condemnation. The book is directed to a minority and is relatively short composed of 62 sections, mainly devoted to attacking Christianity in its institutional form.