How is the Novatianism belief self-contradictory?

Answer 1

Because while it refused forgiveness to "the lapsed" (those who denied Christ or offered sacrifices to idols in the face of Roman persecution, after the person had received baptism) it was also focused on forgiveness of sins and the power of the church and the confessors to forgive. It would also offer baptism and forgiveness to those who wished to convert. In a sense, it only offered forgiveness to those who did not believe in Christ, those who did believe were forbidden forgiveness.